My $0.02 -

1 - Have never noticed a problem with my center rear channel, but like gonk said, I don't know that I would. How much deep bass is sent to rear surrounds anyway? I can't imagine it's a lot.

2 - gonk and synthfreek seem to be responding to two different issues, and I agree with both of them. I've never experienced a total loss of sound when switching inputs like some early users reported. I have noticed, since I also leave my 6.1 on most of the time, the second or two of loss in the same scenarios synthfreek mentioned. Absolutely nothing worth getting upset over (we are talking about menu navigation and children's games).

3 - Don't ever use ambience modes. I toggle through them once in a while when I hit the wrong button and need to get back where I want to be. There seems to be subtle differences between them but I don't ever stop and listen to be sure. If you don't really ever use different modes, I wouldn't worry about it.

I just purchased my unit earlier this year and have been VERY happy with it. You get a month to try it out so if these are your only concerns, I'd give it a listen. I think you'll be very happy with the results.

Good luck!