I have had so much trouble with Vista that I considered a Mac, but I’d have invest in thousands of $ of new software.
Not worth it.
Windows 7, which is due for release this fall, supposedly has solved a lot of the Vista problems.
You don’t need to invest in new software. You can boot native in Windows on Macs, and that has been the case for several years now.
Vista SP2 solved most of the problems of the original Vista. Heck Vista SP1 solved most of Vista’s problems. Have you upgraded to SP1 at least, or SP2 yet?
Get the Mac... then invest an additional $79 in either Parallels or Fusion and run all of your software within Windows in a virtual machine with a slight performance hit over running natively (about 5%). Or you can install your licensed copy of Windows on a partition and run Windows natively. Use the Mac to safely do anything that might infect a Windows machine.
You can run Vista on a mac and it will run better than it will on a Pc. I’ve personally stayed with XP on my MacBookPro running Parellels(the layer windows needs to run) because my embroidery software was designed for it and rather than have to fight with any upgrade and pray that it still will work...