Well I have a 64bit capable PC, installed WinX64 on it - all was good. Installed the apps on it (none of them 64 bit yet) but they were all running great.
Installed Yamaha mLan and Edirol 64 bits drivers - everything running perfect...
Then Time to find 64 driver for my UAD-1 card, Virus and various other bits... erm - none available.
The trouble with 64 bit at this time is that alot of companies seem to be holding off doing the drivers until Vista is out *AND* the major DAWs have all got a 64 bit version out.
You CANNOT install 32 bit drivers on a 64bit OS. While 32 bit applications will run fine (and in the short time I was running it, they seemed noticeably faster), the drivers *MUST* be 64bit.
ASIO is not currently defined for 64 bit either, not are VSTs. VSTs will run run on a 32bit host under a 64bit OS, and even run fine on 64bit version of Sonar 5 (the only PC DAW with a 64bit version out). For both of these, Steinberg seem to be planning a Cubase 4 + 64bit release late this year.
Personally, I think that its fair enough for companies to not do 64bit versions of their apps, but lack of drivers is somethign I (as a user) find *deeply* irratating given how long companies have had to get ready for this and that there is no option to use 32 bit drivers. A similar argument can be level at the slow support for the intel mac platforms as well.
To give an example of the level of unawareness of this - one company's technical support even told me to try out the 32 bit drivers - evidently they were completely unaware of the need for 64 bit drivers - this wasnt some noddy little unheard of company, but a major one in the pro-audio field whos PCI cards many of us here use.
X64 has been out for 6 months or so - there is hardly a current consumer type card/device that doesnt have good stable 64 bit drivers, and yet in our 'pro-audio' market, its the opposite - hardly any have released them. And that is crazy - audio applications benefit hugely from X64 - more so IMHO than current games, web browsing office and all the other random stuff people do with their PCs.
I have to admit, if I had actually had to go out and buy X64 and found it unuseable due to lack of drivers, I would have been very annoy at the waste of money. Thanksfully I dont have to suffer that due to a work provided MSDN sub. If I had purposely bought the PC for 64bit - well.. lets not go there...
So, my advice - it you want to buy a 64 bit machine right now, *FIRST* check that every device that you have/will purchase has a suitable stable 64bit driver available for it. Graphics and consumer audio cards should be fine. ATI, nVidia and Creative have all had drivers out for a while.
That being the case, then go for it - the performance improvements that I noticed in the few days I was running it were well worth it even running 32 bit apps.
In the end - Im back running WinXP on a 64 bit capable intel dual core machine - Grrrrr!
Still its a nice fast and quiet machine for audio work
BTW - if you are thinking of building a machine, I can definately recommend this case:
Antec P180
Mine has a 10000 rpm HD, 2x7200RPM HDs, 3 fans + gfx board and CPU fans, and its still acceptably quiet. None of the usual rattles at all. Cant even hear the hard drives - 10000rpm drives normally make a hell of a racket.