Considering the original drivers from ATI for the HD 5800 series card were pretty much a 9.10 beta, it doesn't come as too much of a surprise that there's limited difference between the two sets. With that said, though, it's disappointing to see the performance under Vantage has dropped on both the cards. Hopefully this is something that will be fixed; we tested it multiple times, re-installed the drivers for a second time and the numbers were consistently slightly lower.
As for new features, we're not sure if they're something that's going to interest you; they will no doubt be beneficial to a certain crowd, but not everyone is interested in AA or Windows 7.
As for performance of the new drivers compared to the previous ones when looking at a HD 4800 series card, we see that performance is the same to slightly better. With a normal array of bug fixes and what not, there's no real reason not to upgrade to the latest set.
It's disappointing and to be honest slightly confusing to find that the new HD 5700 weren't included in the driver set. We had all intentions of including the model this month, but instead we'll add it next month in which it will replace the HD 4890.
If you're looking at the drivers yourself and notice something worth mentioning, make sure you drop a line in our forums; it's simply impossible to test every card on every game, so it's good to hear from gamers out there.
Until next month, happy gaming and benchmarking.