I tried Linux with a win2000 emulator some time ago, and found it very frustrating, as not all windows apps that I use at work would run. Linux is great for Linux apps, but not if you need to use a lot of windows apps, in my opinion (we have a lot of instruments with software written for windows).

I have no personal experience with vista, but recently bought both my kids vista boxes and they love them, very stable, but I did get them high end configs in terms of lots of memory, fast dual processors, etc (from IBM/lenovo). Also, they have the current office2007 vs the earlier versions which may be important (but data can be saved in office2003 to send to colleagues running earlier versions). They use theirs on the MIT and Wellesley networks, and have not experienced any problems. Maybe you just need to get used to it, or upgrade some memory and/or softward.