At a personal level, I find nothing wrong with fast bullets (as long as they can "hold together") I just like BIG fast bullets; recoil --- no particularly big deal!
I really agree with you here. I think bigger bullets really need to be faster. Thats why 7 mags and 300 mags are so much more devastating than say a 30-06 or 308 The 300 is using the same exact bullet as the -06 and .308 but at a much faster velocity.
The faster the bullet the more expansion, the bigger the expansion the bigger the wound channel the bigger the wound channel the faster it kills. heres a pic on velocity and expansion.
No mention of energy when showing the rates of expansion.