Having shot game with all 3 mentioned ('06, 270 and 7-08) and the fact that there is not much difference between them trajectory wise, you do not really need to change from your '06.
But, if I were to pick between the 270 and 7-08, for as much as I like the 7-08, I like the 270 better. I'll admit I have limited experience with the 7-08 only taking a few animals with it. And it was very effective. But I have killed a lot of game with the 270 from distances literally point blank to way out there and it has never let me down.