Mike, I know that you wrote that you've "just got to try it!", but you've also invited "last words" and want to know what "SQ difference" you should get. Factually, you should get none. You've already reported that your 7200 drives your M80s louder than you can tolerate. The difference between 100 and 150 watts in maximum loudness is only about 1.8dB. Note also that the HK rating is somewhat conservative and that continuous power into 4ohms is likely on the order of 200 watts. The two channels of the 3480 are essentially similar to the channels of the 7200 and would provide equally transparent amplification. Your M80s are already wide awake from what you report, so spending money on unused amp headroom isn't necessary to remedy a non-existant slumber.
