I am curious who on here owns the adjustable FPR from pfyc.com

Does it use the manifold vac/pressure to drive the fuel pressure up as the boost rises, or with the N/A engines, as the vacuum goes toward atmospheric, or is it only a manually adjustable unit?

you have to specifically purchase a rising rate FPR that references boost, and they're usually on a 1:1 ratio. You'll note the difference in pictures as you'll often be able to see the barbed vacuum line fitting on the side.

Boost-referenced FPR's are often WAY more expensive than a normal one, but if you're going boosted, I would recommend it.

Bottom line, make sure the description specifies "boost referenced" or "rising rate"

Picture: Aeromotive boost referenced, 30-60psi range (just an example)

I actually found one that isn't to expensive and it looks very well made. http://www.cartech.net/fmu2020.htm

I'll probably end up going with that one or the one you posted.

The Cartech unit you have posted a link is used on conjuction with the factory FPR.

An FMU is used to raise the fuel pressure beyond what the OEM FPR can produce and usually at a higher rate than 1:1, most FMUs are 8:1 (for every one posund of boost refernced, the fuel pressure rises by 8 PSIG rail pressure.) or more. The Cartech is adjustable in this area. This is a decent way, if you will not be changing in jectors and/or will not have an ECM/PCM tune done. Also usually only used for lower boost vehicles, usually less than 8 PSIG or so.