I've had two MRX 700's now, waiting for a third.
The first had a "gurgling" noise from the left rear channel. exchanged it with the dealer after exactly a week.
The second has a "sizzling" static noise in the front left channel. This developed after a week. The noise changes volume on it's own (NOT related to input, volume, ARC, etc.) AND can go to all 5 channels on occasion. It IS also in the headphones when I use them. The 700 also "acts" up. When it's like that I hear some light crackling noise during 30 second skips and have codec lock "POPS" , similar to what I had BEFORE 50.23 FW, but not as extreme.
My 700 can also be a little erratic in sound quality. Bass can come and go in quantity. I was playing with speaker distance and suddenly it "kicked" in a little more.....strange. i also feel when these "channel noises" happen you get a degradation of channel separation, especially to the rears. When I replaced my first 700 with the second I noticed a significant SQ improvement. I should note I didn't have the noise in the FL channel when I initially hooked it up.
I've tried EVERYTHING, disconnected all wires, reconnected, plugged it in even at the dealer you can hear it.
As far as CS, well, I've had the current unit for 3 1/2 months. Finally, Anthem forced the dealer over to hear it. But......you know.........the usual waste of....... "they're all like that" "you should hear what I do at the store" "I can't hear it in the headphones" (easiest to hear in headphone, by the way). trust me, It's not the typical, amp noise, you get with cheap amps. Plus, it changes all the time. 1 channel, then 5 channels, volume, etc.
I've had 3 different, other AVR's in this place over 8 years, including a Marantz 5006 (from BB, just to try it), it worked fine, although the SQ was easily inferior to the Anthem. This is why I'm "trying" to not buy the typical brands.
After my experience, I can see why people just buy Japanese. They are cheaper, more reliable (codec POPs and such) available everywhere. There are few dealers for the "boutique", non-Jap brands. They rarely have ANYTHING in stock or up to date. Most are installers, who aren't too interested, especially if you mainly want to check one out. Others, work out of their basement or garage - Literally!!! I'm STILL trying to get my hands on an ARCAM 360 or 400 just to try it at home, see if I have codec POP's like a lot of people complain about. It's amazing, no wonder they are all having a hard time. Quality plus difficult availability means low sales. I live in a 3 million metro, I can't imagine what it's like in the middle of North Dakota. Oh well.