A 308 is one of the easiest rounds to load for and in my experience many powders work well. I've had good luck with IMR4064, both IMR and H4895, Ramshot TAC and RL-15. I've settled on Varget for my go to loads with heavier 150-165 gr bullets and TAC for 130's.
Velocity and acuracy between any of the above has been pretty close, but I prefer Varget or H-4895 because those 2 are formulated to give consistent velocity over a wide range of temperatures. You could see 100 fps difference between summer and winter velocity with some powders.
I tried some RL-17 in my 300 WSM. Velocity was super. A max load was over 130 fps faster than a max load of H4350. But accuracy was not acceptable in my applicaton. It could work fine for someone else in a different rifle. I don't think it would be a good choice for a 308, but would be interested to hear reports from anyone who has tried it.