Thanks everyone for the great welcome and response!
Well you gus and gals have made my mind up!
I've had a copy of vista Ultimate x64 ready to install, and downloaded all my device drivers
for it, so hopefully it should all be good to go.
I've got the apps I use now with vista ready versions and where possible x64 versions.
I dont really have any games just lots of 3d modelling and cad software which are all certified vista ready and compatible, so that should be cool
I've been saving a nice 15K scsi drive for this so hopefully since Windows 7 has been stripped of some of it's flab, it should hopefully boot like a rocket!
Also I've been reading that it's got a feature that allows people with poor eyesight to still use large resolution monitors buy adjusting font sizes within all apps and windows - my partner has poor eyesight and at the moment we use a resolution manager to allow her user profile to load at 786 x 1024 instead of the monitor's native 1200 x 1600.
If this is the case, then it beats apples equivalent hands down
Anyway thanks for the votes of confidence, you've made my mind up for me!