Yes, I agree there is overlap, no question about it. My main reasons for this are an all-weather rifle and a more mainstream caliber. I do not hand load, and factory ammunition for the 08 and 260 for premium stuff is pretty expensive to go out and blast away. I know, I know, it's my fault for not being a reloader, but I just haven't found the time for it, and I can afford to buy the stuff, but still it gets pricey.
I'm sure I can find ammunition in 270 and 30-06 on most shelves, but at the shop I frequent they only had two boxes of 7mm-08 and no 260. I just ordered a bunch of ammo in 7mm-08 and 260 from Midway. I got 27 boxes of assorted ammunition and it was $1100, and they were out of most of what was listed on their website, and weren't taking backorders. I'm hoping that won't be the case with the long action calibers we're talking about.