ARC Ref 6 + Boulder 1160

I’m using ARC Ref 6 with Pass Labs X-350.8, and I’m very happy this combination. One of my friend are interested to use ARC Ref 10 and Boulder 1160 amp, but we can't find anybody use this combination in my region.  Does anybody who have listen to similar combination such as Ref 5 SE/ Ref 6/ 40th Anniversary Edition Ref/ Ref 10 with Boulder amp? How’s the sound quality? And how does it compare with ARC Ref pre-amp with Pass amp? Thanks