I am not saying a good center channel amplifier isn't important it is. However, what you are looking for is a competent one. The difference in sound for Home Theater between the amplifiers would be more difficult to notice while the difference in having or not having a center channel or having a good vs. a better one are different arguments.
In a high performance music system where the two main speakers run the entire show; the more subtle differences between the two amplifiers would be more clearly defined as you have verified, in a home theater experience the very fact that all five speakers are playing at the same time makes it much harder to pin point any differences in amplifier quality between the center channel and the mains. In an ideal world you would have similar amplifiers or better yet the same one for the center.
I haven't heard the Ayre mono's, I did do a comparison of a customers' Ayre V5X vs. my Edge and it was no contest. I have no idea what part of the country you are in, but if you can find a Plinius dealer you should take a serious listen to their SA 103, which is a 125 pure class A amplifier which sells for a very reasonable $6,395.00. We just got our demo amplifier in which I am running with my Dali MS 4 and the combination is pretty amazing. Plinius makes some of the finest sounding solid state gear around and their prices are insanely cheap for what you are getting with most of their products.
I hope this helps.