I appreciate the retraction, sometimes it gets very annoying with just the knee jerk reaction to blame microsoft for anything, or to say vista is nothing more than some old paint slapped onto xp. Vista has many issues, and it'll certainly be better after a service pack or two, but it is a marked improvement from xp, which, IMHO, sucked right up until SP2. Gold XP was buggy as hell, and some of those bugs still exist in xp today. remove the go button from explorer.exe and then resize the window wide and drop down the drop down addressbar and you'll see what i mean. vista's explorer.exe, while slower, is much less buggy.
Anyway.... vista could definately have done with a longer dev cycle. Vista was devloped in only 3 years, as almost everything up to 2004 got scrapped after MS realised it wasn't going to work.
of the work is done under the hood in changing and compartmentalizing the codebase, removing cyclical dependencies, et al. I'm sure this work will continue with Windows 7, to be released in 2009.
As for the driver issues, well, look at those charts. The variance is not ranked by performance, indeed, a **** card, the x1300, performs the same under vista than under xp. It's varying wildly across chipsets and performance levels. That indicates to me, driver level issues.
So, i'll concede that Vista opengl drivers, depending on your card, might not be as good as on XP. But in my case (as in the x1300) I haven't noticed any slowdown. Since anandtech only bothered to test currently available cards, we don't have an idea of how drivers perform for older cards.
On the other hand, direct X cards are mostly better. slightly. But as you can see 8800 owners are still bitter with many games just not running. I think the graphics cards guys need to be fully responsible for this; it's part of charging 300 to 700 dollars for a piece of hardware manufactured for up to 130 dollars max in many cases. You owe the customer what you say on the box.
Keep in mind too, that the nvidia driver encompases almost 20 million lines of code. That is almost as much as NT 4.0 itself. It's not a trivial manner to deal with such a massive codebase for so many cards. This is why nvidia is starting to drop support. Their whole unified driver approach is beginning to come apart as well.
As for OpenGL vs DirectX, it's obvious to anyone that most games use DirectX. Becasue of that, it'll recieve more coding time and resources and be a bigger priority for the companies to get right.