Eclipse 3.2 has known issues with Vista. I run Flex Builder as a plugin and Eclipse crashes about 10-15x per day on average.
3.3 addresses this issue and runs VERY stable and fast on Vista. Unfortunately Flex Builder has serious issues with 3.3, it wont even build. So if you can deal with the crashes, yes, its feasible to run your desired environment on Vista. I've been doing it for 5 months
