I use varget for both, for .308 it is fantastic.
For .223 I use 77gn SMK's, and have done load workup using , H335, Varget, and N540. After ~ 100 test loads I found very little difference.
When I switched to 73gn Berger VLD's I found a very slight benefit for N540.
When I was using 75gn Amax bullets, I found that the loads were a bit compressed with varget, solved that with a longer drop tube.
I just use varget for both now