Looking at the burn rate charts, I would think Varget would be better with lighter weight bullets. My friend is working up loads for his .308 gasser and he tried Varget with 150 and under bullets with so-so results. I gave him some 168 Sierras and a pound of 4064 and he found pay dirt with that combo.
I'm trying Varget with the new Sierra 169 gr MK and so far it is acceptable, but not nearly as accurate as the IMR 4064/Sierra 168MK combo. That could be an issue with bullet tuning on the new 169's though. Too cold for me to go to a range right now. 5 degrees does not make a comfortable day at the range, lol.