We also did some side by side cuts with two 044s. One was a 10mm and the other a 12mm. The 12mm had a dual port muffler cover, the 10mm had a stock cover but appeared to have the exit hole opened up somewhat on the muffler, so essentially equivalent. There was no noticeable difference between the two. (videos may show a slight time difference)
These saws were both set up with brand new bars and chains that had never seen wood so it was a pretty fair comparison. I had planned to sell one of these saws and didn't really care which one I kept. This test seemed to confirm the lack of remarkable difference between the two.
I have seen some very strong running 12 mms, and I don't think the pin size makes any difference at all. I just think the 10 mms are a good indication of a good cylinder, but if you got a 12 mm with a good cylinder, I'm sure it will run just as strong.
I have also seen some 440s that are not as strong.
Sorry for the delay, but here is my pictures from the weekend. Thank you everyone who helped me get my 372 running. I still haven't had the chance to play around with the carb on the Stihl MS261. But man, does my 372 run good thanks to Cory's tune up job.