Can't go wrong either way. Never heard the 800, but I love my 500, goes low enough for me and most people (does a great job of shaking my house). I would consider a 2nd. My vote goes to the two 500s. Granted one 500 is still very powerful! Just more flexability and options. Also, not as heavy and bulky.

pn

paul

Axiom M80, VP180, Qs8, EP500
Epson 3020
Rotel RB-880
Denon AVR-990