order from billlawrence.com and you'll get the p.ups that were originally mounted on Dime's guitars (and N4s)
order from billlawrenceusa.com you'll get the p.ups made by Bill's former partner
these are sometimes quoted "FAKE" which is not exactly right: Bill's partner managed to keep the name "Bill Lawrence" even after Bill's departure from the company they had set up (there was a trial).
YET: they are not exactly the same in design, output and overall quality.
I heard samples of the L500 made by Bill's former partner and I read reviews.
I decided to go for Bill's p.ups (the "original") and I am not disappointed.
rich tone, plenty of harmonics etcetc.
But I must say that Bill's website is not exactly StewMac... it's not a 2.0 website with flashy effects everywhere either.
In my mind, ordering from Bill is like being part of a small club of people "in the know" whereas shopping from Bill's ex partner website is like going to wallmart
you may also be interested in taking a look at Bareknuckles p.ups.
more expensive but they are amazing...