Can anyone offer advice/info on these two receivers? I'm looking for a new receiver to go with my new M60's and have narrowed it down to these two.

I had originally decided to go with the 525 because of the rich feature set and all the positive reviews I have read about it from owners, but there is one feature on the Yamaha that intrigues me. It is the automatic acoustic optimization feature (YPAO?) that uses a special microphone hooked to the amp to automatically "optimize" speaker output based on the physical position you place the microphone at.

Has anyone used or heard about this Yamaha feature. Is it significant enough to change my initial tendency to go with the HK525?