SYK, I have the Sopra 2's. Have had them a year now and they have really opened up from when I first bought them. It takes some time, don't get discouraged if they don't sound as open and warm as you expected at the onset.
My integrated amps are SA 700i, Hegel 300 and 160. I also had a 600i to demo for a day. The SA 600i beat the 2 Hegels on all levels, but the price point for the SA is much more than even the newer H360 which I have not tried. The Hegel's do sound nice with the Sopra's.
The 700i kills with the Sopra's. Same with the 600i but to a lesser degree. The 700i is a significant step up from the 600i, but you are rewarded with amazing soundstage, speed, depth, clarity, punch and very articulate on the smallest of detail. The 600 is about 80-85% of what the 700i does. Sim and Sopra are a great match.
Good luck.