I have been trying very hard to only use the 2.57 blender, but keep running into bugs. Pretty serious one too, like my UI flashing out of existence; making it near impossible to use. Blender crashes a lot too. I don't know if the 64bit version is any better, but I don't remember having all these problems with that version. All my drivers are up to date, so I guess I'll just have to look forward to a more stable version to come out soon. I really wish it worked better. I love the new UI and all the really cool improvements.
I guess this thread is for venting Blender frustrations.