Hey all, I also still use my Atari equipment. Because I have it, I use a 7200 on my Panasonic 60" ST50 to play games on, since I can play both 2600 and 7800 games. We do not have the sound sent back to the receiver, really no need for any more than what's coming from the TV speakers. Kaboom is my favorite game, so it is what is usually being played. Picture is fantastic and there's no lag at all.
Here's a little background, I've been an Atari fan since I was a kid. I scraped and scraped and bought my first one not too long after release. I currently have 6 2600 consoles, mostly VCS's. I haven't looked to see if any of them are heavy sixers, because I don't feel like unboxing all that stuff to see what's in there. I have one 2800, complete with the controllers, two 5200's and one 5200 trak ball controller, and three 7800's. I have more games and controllers than I feel like counting.
I was also quite the Atari computer fan, although I was a C=64 guy during the 8 bit days. On the Atari side, I've owned them from the original 520 with TOS on disk and a single sided floppy drive, through a 1040ST, 1040STe, Mega STe, Falcon, and a TT/030. I had a setup with dual monitors (monochrome and color) up until I was able to get a Moniterm for my TT/030 - I did mostly DTP so this was perfect for me. I also ran an Atari BBS, on Ratsoft BBS.
I was able to obtain a lot of this while I was working for an Atari repair shop back in the early 90's. We did all sorts of board level repairs, even memory upgrades on the Atari Portfolio.
I see he does 7800s too. I may have to send one in! My receiver does the upconversion.