In case you want to use some extra hardware with your computer like TV Cards or usb devices like Cameras you should check whether you can download 64bit drivers.
64bit Windows runs quite fine most programs will be compatible and some are already available as 64bit versions. But when it comes to driver supports many manufactors still don't provide only beta drivers or even none at all.
I've had problems in the past with Creative drivers, TV Card drivers, Webcam drivers, IBM DB2 software (32bit version 64bit versiona available)
I have Vista 64 installed on my machine too. Intel RAID0 same cpu as you have and my pc keeps resetting with the Vista built-in RAID driver for the Intel chipset. Haven't tried to install a newer driver though.
If all needed drivers are available I'd definatly give 64bit a try cause it runs much smoother than 32bit Windows :-)