Is the Adcom GFP-750 really that good ?

I own the Adcom, bought it new.
The features are nice, the sound is great.
The passive is great, if I want a little more "boogie" the option with gain rocks. The fact that the preamp (with the flick of a switch) can "pass" the signal to another device, then get it back, makes it great for that music/media dual system.
I would say for the price, you get a worthwhile preamp.
I have NO plans to dump mine anytime soon!

Try a used Parasound P/LD-2000 -- I had the Adcom and like the P/LD-2000 better. It seems to have more body, and is a bit more musical (while retaining detail). By comparison the Adcom sounds dry and thin. Others who I've spoken to who have tried both say the same thing. I think the Adcom is a very good unit for the money, but I also feel it's somewhat overrated.

I bought the Adcom used on Audiogon. Made a big difference
in my system. It's worth the money. I love it.