I don't use many IMR powders anymore. No particular reason but I've been having such good results with Varget and H4350. That being said, my 6 Dasher prefers IMR 4166 and it has given great results for me with 107 grain Sierra MKs.
I've used 4451 in 6.5 Creed w/ 140 and 123gr bullets. It seems to yield less velocity for me than H4350, but it is pretty temp stable, and it seems to be consistent. Not a problem to get an accurate load with a wide node. I've switched to H4350 for competition loads, but I have no hesitation in using 4451 if I run short on H4350 somehow.