I try to stick with 130s in the .270 Win. That's what the cartridge was designed around, and where it really shines.
If you want something like a Trophy Bonded Bear Claw, you'll have to step up to 140s, but I try to avoid anything 150gr or heavier. It's a .270. If you want to shoot 150s, buy an '06 (or .270 Weatherby).
Whatever you decide upon - If you end up using Barnes bullets, don't shoot the closest weight to your preference. For example: If you decide to stick with 150s for cup-and-core bullets, don't shoot the 140gr and 150gr Barnes bullets. Go with the 130gr, instead.
If you decide to stick with 130gr cup-and-core bullets, don't shoot the 120-130gr Barnes stuff. Shoot the 110gr, instead.
Barnes bullets are considerably longer than standard designs. A 110gr TSX will 'act' like standard 130gr bullets, and a 130gr TSX will 'act' like standard 150gr bullets.
(Similar reasoning applies to other brands of solid copper bullets, but the weights and substitutions may be a little different.)
Premium bullets aside-
When everything seems to be falling apart on me (including my own loads), I can always fall back to the 130gr Remington Core-Lokt factory load.