Back on topic, since I don't think the emo's have been giving you problems in quite awhile, why change? Also, why the NHT? Just weight?
The IPS-1 has always hummed. I had disconnected four of the seven amp modules to reduce it (and cherry picked the quietest three modules), and that worked pretty well. Once I reconnected two of the others for my new surround speakers, it's a bit louder again. After five years, I'm just tired of turning it on and off when I turn my receiver on and off (it hums just as loud in standby).
That, and like you mentioned, I really like the idea of a lighter amp.
Because I also want XT32, I'm wondering if I should just buy the Denon 4520 and call it a day.