Welcome to the forum!
Quick question - you say that you had issues when streaming video. Do you mean passing video through the Onkyo receiver, or do you mean streaming video over your network? If you're talking about streaming over a network, it might have had nothing to do with the receiver.
As for your question between those two receivers, I own the 626. I think it's a good receiver. There are reviews of it getting hot and/or having issues. I didn't experience that while I was using it, but there are enough of those reviews to make me believe it's a real issue with some of the units.