I'm just a first year beek but here's my take on this:
I bought 2 Russian nucs and 2 Ontario (Italian) nucs last May. I got surplus honey from all 4 hives. Both breeds were equally gentle. On a rare occasion I worked the hives during bad weather (a no-no but it couldn't be avoided) and I would say that the Russians were a tad more defensive during bad weather. Russians are darker and a little smaller than the Italians. I keep them in 2 yards 7 miles apart. The Russians always seemed to have queen cells on the go. As far as wintering goes I will have to wait until the spring to see which breed fared better.
One thing I did notice though was that the Russians took down less syrup and took it down slower than the Italians in both spring and fall. Russians were slower to build comb. I also noticed that more of them foraged on cooler days than the Italians. Propolis usage was about the same but bridge comb was a bigger problem with the Italians.
Shoot for the moon. Even if you miss you`ll be among the stars!