ARC REF 150SE vs REF 160S

I moved from the Ref 150 to Ref 150 with KT 150s which ARC reps told me was almost as good as the Ref 150se. Then I moved up to Ref160 monos. There was a difference between my Ref 150 with KT150s and the Ref 160 monos but it was maybe 15 percent for twice the price. I assume the Ref 160s would be in the range of 10 to 12 percent better than your amp. It will be a noticeable difference but not a huge difference.
But when you move up from the fabulous Ref 150 to any amp in that power range, you reach the point of diminishing returns. 
The the price for the improvement is dear and not  mathematically proportionate to the gains.  Would I do it again? Hell yes.

bifwynne
You could very well be right. My Ref 150 with KT150s was one sweet little brut. I'm sure the Ref150SE was better.
 I maintain that the Ref 150 series amps from ARC are among the best bang for the buck (now used) gear in high end audio. Of course, my comments do not any account for the fact that the monos do have imaging and stereo separation that a stereo amp cannot match -but as for other aspects of sound, there are diminishing returns. That said, I do not regret the purchase of the monos.