If bass is important to you (guessing so from your user name)- then go with the 500 over the 350. I think 1 500 will give you more than even 2 350's. Granted, I haven't heard the 350 myself but the 500 is plenty powerful for most, and the extension is lower.

-Dave

M80s VP150 QS8s EP500s
ravenmanor.com/cinema/