I am currently running a 1050 with a old Parasound 1200IIa (205 wpc) driving my NHT VT1.4 mains. I am trying to position myself to replace the 1050 with a separate pre-pro and am looking for am amp that would primarily handle the center and surround speaker loads. Currently, I am running NHT SuperZeros for the rear center and side surrounds and a NHT VS1.4 for the front center. Both amps are right in the middle of the recommended power range for these speakers.

From a spec perspective the Parasound appears to be slightly quieter (< .03 THD vs < .05) and slightly more powerful 85wpc albeit in a 5 channel mode. From a price perspective the used 855 is about half the price of a new 7075. I am not sure that I would ever use the two additional channels of the 7075 except as emergency backup in the event my 1200 failed.

Given this, what are anyone's thoughts on a 7075 versus a used Parasound 855. Do solid state amps age? Also from a WAF would I expect to hear any immediate difference by replacing the 1050's amps with either (again just for the surrounds)?