Gaming Pirate Vista Ultimate or Legal Premium?

[Trolly]

I decided to give Vista a whirl and dual-boot it with XP on my new PC. As it's 64-bit and I have a decent PC, the nice surprise was that it's boots up almost instantly (no boot loading screen shows for me!). It has some useful new features, which is great. And Ultimate (and Premium) comes with Media Center also, which is a nice surprise.
I was miffed to see space pinball's disappeared in Vista though. And a driver nightmare approached! Because is turns out my wireless USB dongle has been outdated, and so there are no Vista drivers so I couldn't connect to the internet. Then My Book (Plug n' Play) drivers wouldn't install the first few times I booted up, but now they work thankfully. Overall it's been a pain re-installing so much stuff even on a dual-boot machine (but then that's not Vista's fault).
I guess, in my brief experience in Vista, I found there wasn't a huge difference between Vista and XP. Vista's biggest weakness is a lack of driver support I reckon, though if you build a PC in prior knowledge of you having Vista that shouldn't be a problem. As for people saying Vista is full of bugs and is really slow, though I haven't spent much time with Vista, I found those points to be untrue. Vista was faster on my machine, and I came across no bugs or problems.
The last advantage to Vista (DirectX 10) is practically pointless now. As no games take full advantage of it really, those that do (Bioshock and Crysis) have a large performance hit for pretty much no improvement.

Here are my specs, just incase you need to know:
AMD Athlon 64 X2 5200+ - 2.7GHz
2.00GB 800MHz DDR 2 RAM
ATI Radeon HD 3870 512MB
Asus M3A

EDIT:
Oh yeah, sorry I went off topic. Only get Ultimate if you particularly need the shiny new SP1 or the extra special features on it that are practically pointless. Premium has all the decent stuff already.