The comments in this thread were based on using the 1070 with Ascend 340 classics (and 170 surrounds) and an SVS sub.

http://ubb.outlawaudio.com/ubb/ultimatebb.php?/ubb/get_topic/f/37/t/000129.html

I found the performance to be very good for music and movies, but I never tried games on my system.