I say no. But, unlike most Americans, I don't have any particular allegiance to the 277 bore. Give me any of the 264 bores any day...

The standard case of the 260 will always give it an advantage for re-barrelability (if that's a word). Also, the 260s ability to handle 100 gr bullets of respectable SD make it a superior long range deer/antelope threat.

Anyway...

Whatta you think. Also, what are the real differences between the two?

Not even close. Think of the 6.8 as a necked down 7.62x39. Case capacity is about 30 grains, less than 2/3'rds of the 260 case. The 6.8 is interesting, but it's not in the same class as the 308 based cartridges. JMO, Dutch.