Which Vista version to use

[Check]

With SP1 coming out soon (or something like that) I've been contemplating the upgrade to Vista.

Before getting into the actual question at hand a few of short ones.
1)I plan on installing 64bit, however if I'm not satisfied with it, can I install 32bit using the same disc and cd key?
2)OEM or Retail? Will I be able to reinstall the OEM version down the line once I upgrade my motherboard, processor, video card, etc. Or is the OEM version linked with whatever hardware I have at the time and I'm out of luck once I upgrade?
3)How much space does it require? I usually make a separate partition for my OS so I can blow it out and start from scratch without worrying about backing up files or installs.

And now for the real question:
Premium or Ultimate?

After looking at the comparison chart of different versions I can't seem to figure out any reason why I would want Ultimate. I don't ever see myself sending or receiving a fax, especially since I don't have a modem. The only thing I might miss is Remote Desktop, but I should be able to use VNC if I want access to that.

Are there some advantages to Ultimate that Microsoft doesn't mention? Added utilities I might find useful, extra advanced options, better compatibility/stability?

I really don't see how they justify charging so much extra for what seems to be so little.

 

[mechBgon]

1) if you get Retail, you're cleared to use either 32-bit or 64-bit. Ultimate is the only version where the retail package actually contains both the 32-bit and 64-bit DVDs; for other versions, you send away for the 64-bit DVD if you want it. Don't ask me, I didn't do it

2) OEM is intended to be used on one computer forevar, and Microsoft says the motherboard is where you generally draw the line (other than outright failures where you can't get an exact replacement). If you want to be completely free from these sorts of restrictions, Retail does that for you.



Ultimate has image-based backup so you can recover the entire system from a backup if necessary, Shadow Copy (you can go back in time to get older copies of stuff), can join domains, and the Retail version comes with both DVDs in the container already. Plus your license allows you to run your same Ultimate license inside of virtual machines. I also like the option to use a Software Restriction Policy, a side effect of having editable local group policy.

You could start with Home Premium and then do an Anytime Upgrade to Ultimate later, but I'm not sure that's the cost-effective way to go.