I havent seen really any differences in 8.0 from what I can see...
but back to the why on 7.6...
due to the nature of what we do we cannot be on the lates more so to let the bugs work out first and secondly it takes us a LOOOOONG time to upgrade. When we were going to go 7.1, it took so long we ended up stopping our meetings, etc to review 7.1 SP1. While some think that is minor, it is large for us.
the whole thing about no licenses was for a different group to show them what they can do with it for now and maybe get licenses in the future. I setup the 8.0 environment and they havent used it yet as they are so busy.