They are praised as one of those "absolute pinnacles" of vintage tone. I only had a guitar on my hands with Lollar Imperials and, in my opinion, they are great. They are not, however, made of some transcending substance that ages them some 50-odd years so that they transform your Les Paul into an original '59 - they are smooth, vintage voiced, and rather dynamic pickups, albeit expensive little buggers. Considering the number of quality British pickup manufacturers, I'm unsure whether it would be worth it to fork the extra cash.
I haven't heard any aftermarket pickups that added a whole lot to the fender american standard pickups.
Lollar, Amstrong, Häussel, Van Zandt, etc... all very good quality pickups, but why change something that isn't broken?
I think players often blame pickups for lack of decent pickup height setting, then they get a guitar tech to install new pickups and the guitar tech sets the height and suddenly the new pickups sound much better... LOL
I also think pickups, especially single coils, are often mistreated, many players take no care whatsoever in arranging their pedal chain for impedance matching or signal integrity, use weird cables, etc... on single coils, that results in too much pickup load and bad pickup performance. Then they get texas specials or some aftermarket pickups with more inductance, and they think that the new pickups are sooo much better... while in reality the higher inductance pickups have a more limited dynamic and frequency range, but don't suffer as much from the tonesuck of the signal chain.
But other than that... whatever works... taste cannot be succesfully discussed.
I do have to say that I think that the more vintage handwound pickups are (and I compare it with the handwound pickups I have in my FCS Masterbuilds, which are exactly the same spec and wound by the same woman that wound the custom shop pickups in the sixties) much more difficult to use. On a clean amp they sound great, very airy, dimensional and woody, and everything comes through very naturally, almost acoustic, but once some distortion comes into play, they behave quite erratically and have a lot of odd resonant frequencies that make playing unnecessarily difficult. For jazz or country they are superb though, really takes the breath away, and they are cheaper than Lollar pickups which aren't handwound.
As I said, taste is very hard to discuss, but I kinda like the balanced specs of am std single coils, they age really great, definitely sound woodier and more delicate after 15 years or so, they don't break, and are universally usable. In the nineties, when my first am std strat was still not broken in properly because it was only like 3 or 4 years old, I still found the pickups to be a bit too harsh, so when I bought another am std, I put in Häussel pickups. These sounded great from day one, really great, but now, my first strat is 16 years old, hasn't been modded in any way, and it sounds waaaay better than my 13 year old strat with the Häussel pickups, which hasn't changed in tone to my ears, and now sounds much less woody and touch sensitive than the first. So it all depends from one instrument to the other, from one pickup to the other. My strat has been gigged a lot, so it has been subject to much more temperature shocks, vibrations and exposure to magnetic fields than players that only play in their house, so the pickups in my strat definitely aged in a different way. I think it's all very complex, and that pickups that are all basically clones of am std fender pickups with a certain degree of ageing, don't matter that much in my guitars and for my use.
One thing worthy of notice is that Abigail hasn't been doing anything other than feeding the wire to the winder for quite a few years now - she's more of an institution inside an institution, and there's nothing special soundwise, but having Ms. Ybarra be a part of it has its charm, quite definitely. Also, the Fender Custom Shop didn't exist until very recent times. Abigail wound a bazillion pickups as a young worker for everything from Teles to Strats to lap steels, from the lowest to the highest end of whatever range Fender was producing. Her ascendance to the custom shop (although she was already working solely on upper scale US models) took place when it started in 1987.
American standard pickups have been quite different from their original counterpart for over 2 decades, as they have more inductance to deal with the plethora of crap people have been using in the signal chain, yet you can get "vintage spec" pickups as well, which albeit different have a bit more of that "old tone". In all honesty, the standard ones work fine and they resist a lot better to crap conditions without farting out.
The handwound pickups are sub 2.1 Henries and partly crosswound (wire is much more organised than on most handbuild pickups, but it's still visibly handwound, not like the programmed crosswindings of Häussel pickups), not tightwound at all though. They are waxed, but more bucket style than vaccuum potted, the wax is also very visible, but I'm quite sure is modern TPFE style wax (it also smells of teflon and silicones more than of candle wax), certainly not the old style reddish parafine stuff. The wire is different than the wire on the Am Std guitars. The pickups can be bought separately, just like the machine wound Fender Custom Shop pickups, that are always available in three aftermarket series for people that want to change the Am Std pickups in the guitars: the "Vintage" version, which means lower output and staggered polepieces for strat pickups and the tele neck pickup, and smaller polepieces but a hotter pickup with more output for the tele bridge, a texas special version, with hot midheavy pickups for strat and tele, and the noiseless series, depending on what contract Fender has with the patent holders of the various noiseless pickups.
The sound of regular machine wound Fender Custom Shop Vintage sets and the sound of the handwound "Abigail" Fender Custom Shop pickups that are used in the Masterbuild series or that are bought as such, is completely different. The "Fender Custom Shop" is also more like the "J.Custom Ibanez", not a real custom shop at all, but a marketing trick. The real customs are the "masterbuild" guitars, that are made by one master luthier with his own interpretation on the instrument that a customer orders or that he feels like making. I don't like all masterbuilds, but a couple of master luthiers make really great instruments for a very reasonable price for that kind of quality. BUT, these guitars are really hard to manage in modern rock music applications, in fact I like playing my Am Std Fenders much more than my Masterbuilds, which sound great but are way too advanced for my skills.
Seeing as how were talking pickups (In particular fender) I looked at the setting up specs for strat pups on fender site to which they say no less than 2.5mm to the pickup on the first and sixth string, this seems very close for my strat as it has staggered pole pieces, I usually set the pickups really quite low in mine due to the pick hitting them most of the time but I was wondering what the general consensus is on the height for the vintage style staggered pole pups.
I'll take a picture tonight of one my staggered ones and you could compare, but there is no way mine are set to 2.5 mm I think, I would have to measure.
If you follow the official Fender logic (which is certainly not LEO Fender logic imo), you would be required to press down the G-string polepieces into the bobbin, because the staggered vintage polepieces are made for 4 wound strings and 2 unwound strings. Except: in those days when leo fender made the staggered pickups, the strings were not made from nickel steel like now, but from nickel or chrome steel, and those materials behave completely different with regards to magnetic inductance.
I think one of the benefits of single coils is that you can get a very broad range of different response and sound by setting pickup height, from very low to very high. My experience is that when the polepiece are less than 2.8 mm from the strings, stringpull becomes noticeable, and that most of the time the height under the bass strings and height under the treble strings should be set differently for each pickup.
One of the luthiers at Fender told be that it's always best to set the pickup height with the pickups straight parallel to the body until you like the attack, then set the angle of the pickups, so that all three pickups sound like they are in the same guitar. Most of the time, for my guitars that means that the neck pickup is a bit higher on the bass side and the bridge pickup a bit higher on the treble side, and the middle pickup about parallel with the body, but I've seen so many different settings, that I think it depends a lot on the playing style and the geometry of the strings because of action, truss rod, nut, and bridge preferences.
@Fred: LOL, don't you smell the pickups of a new guitar? I can't resist... I have to know how they smell...
My Mollenhauer SST Klassik came with Lollar pickups. they sound phenomenal, but I doubt I could justify the cash outlay of buying a set to upgrade a guitar when there are plenty of other pickups that sound just fine.