I have the Cobalt 816 and I think that they like a lot of power. I had a C350 that I used for a while and it worked ok, but once I upgraded to a bigger amp the sound improved greatly, especially in the bass. Right now I have a Conrad Johnson PV-10B pre and a B&K ST125.2 power amp. I added the CJ first so for a while I was running the CJ as pre with the power section of the C350. But then once I put in the B&K, it was a tremendous difference. Much more weight and authority in the bass, and also a more open, relaxed sound.
I don't know the specs on the Cobalt 810 but if its like the 816, the extra power could make a nice difference.