Brian,
I installed Beta 2 on my laptop as soon as it came out. This current version seems quite stable and fast. I have had the odd issue when copying a large amount of files to a network share and Windows Explorer crashes. Vista does seem to be able to recover from the crashes fairly well.
I would all so recommend having a minimum of 1GB of RAM and probably 2GB would be better if you are running applications.
You may want to consider dual booting Vista with your current O/S on your laptop as a transitional option in case Vista does cause you some grief.
Wayne