I'll have to think about the sound part in comparison to the ones you have....I guess I would say they have tweeters like your advents, really nice detailed mids, but the lows kinda build and really extend. I think that is why they don't do beat driven rock as well. They don't thump like the JBL's, and don't go as low as my EV's (15Hz), but the bass is still low and full. I haven't heard the Avid's or specifically the JBL (but I have heard others in that line). What styles of music do you listen to? If you do acoustic, vocals, jazz, or other mellow stuff this is what they are for. I don't know about classical - not my style.
Your Marantz 2215 won't have enough juice to make them come alive, but the 2230 might. They sound good at low volumes, but really come alive with more power. I didn't really notice it until I hooked them up to my Sansui 8080.
Btw, I love the EV interface series. I have the C's.
As to contacting Fried - I emailed them earlier today and I just got a response. It was short ( four words), but it answered my questions. If you don't get a response today, I would resend and email on monday.