I'm going to chime in here with Enginejoe;
I have exactly what he has, and I think it does an incredible job.
The EP350 blends in beautifully with the M60's on music, and I just turn it up a bit for HT. I find myself shaking my head when reading so many of the posts from the sub crowd. I know everyone has personal preferences, but I have my EP350 in a pretty good sized room, (14X28 or so w/ vaulted ceilings at the end where the system is set up) and it simply blows me away! [censored], last night I ended up in the doghouse because my girfriend was sleeping and I had Pirates of the Caribean on, and it woke her up three times, rattling things on the wall in the bedroom, and I know that I did not even have the sub set past 1/3 on the volume.
I too was on the fence between the 500 and the 350, and now that I have the 350 dialed in, I just cannot imagine wanting anything more.
But, as they say, that is just one man's opinion! I'm sure the Sub crew will begin shouting me down any moment now!
TjB