As far as the magnets losing power over time, that is not what gives a vintage PAF it's mojo. Clapton, Page and Beck used actual Gibson PAFs in the 1960s and their sound is the definitive vintage PAF tone. There is no chance that their alnico magnets weakened in a space of months or a few years... nope, weakened magnets didn't contribute to the sound of the PAF. So are the DP103 pickups that they make today identical to the PAFs that Dimarzio made in the 70's and the early 80's? I doubt it. Guitar World's review of the 36th Anniversary PAF® was lackluster and the pickup came off sounding rather bland and unexciting. Larry redesigned the PAF recently, here's the quote from Dimarzio's website:
The PAF® 36th Anniversary model has the best qualities of the Virtual PAF® and Virtual Hot PAF® pickups and then some. It’s as loud as the VHPAF™, but has as much low-end and midrange definition as the VPAF™ model. The highs are actually bigger and smoother than either model.By Dimarzio's own definition, the current PAF bears little resemblance to their original design. There were deliberate changes made to the materials and production, there is really no way that they can sound the same and they don't, IMHO. Nobody tinkers with their pickup designs like Larry Dimarzio. He is a constant innovator and experimenter. I like Larry's original pickups much like I like "Van Halen I" as opposed to "For Unlawful Carnal Knowledge". The latter my be a better record using high tech recording techniques and the latest trial and error methods of producing superior sounding albums... as well as having Eddie's years of wisdom behind him and the 30+ years of accumulated knowledge to avoid pitfalls and errors. Yet, "Van Halen I" is a superior record because it has mojo.
I have new Dimarzios and older Dimarzios... they all sound crazy different. The newer Dimarzios are truly amazing accomplishments and are extremely innovative. They have a HUGE sound compared to the vintage versions and have very little noise, they are in all respects better pickups. They just lack the sweet harmonics and slightly complex treble of the vintage versions. They also lack the almost acoustic like response of the original PAFs and that almost crystalline like high end that we associate with the vintage tone.
It might all be a placebo effect though... one's ears can fool one into believing something will sound a certain way due to an expectation of a certain outcome. I would swear that they sound different, but I could be wrong and they really don't, I've never been able to do a double blind test.
The vintage PAFs sell for a bit less than a brand new PAF® 36th Anniversary model does... unless they are zebra or have an output higher than 8K, then they don't ever sell for over $150. The only used Dimarzio pickup that consistently sells for over $100 is the Musicman Axis bridge model. Us vintage Dimarzio PAF fans are actually paying less for our pickups and are actually doing the environment a favor by recycling a perfectly good pickup that has already been created.