I have just recently jumped on the 6.5 bandwagon with a .260. So far, I am impressed, but it does not hold a candle to my 7 mag for elk punching.
The .260 is now my favorite deer shooter, edging out my .308s, but I have shot too many elk with 160 Partitions
3000 fps out of the 7 mag, to ever consider pushing it aside for a 6.5.
Both have their place, for sure and both will kill. I just like a little more punch for bigger stuff.