I just want to add. Mine was a bit stuttering after the 64bit patch, but playable. Both 32bit and 64bit the same. The most difference is the client are less ram and my pc works more leisurely 
BUT
After 30April’s patch, 64bit become more and more stutter. 32bit a bit more stuttering than before.
I wonder if I should send a ticket. I hope Staff respond this thread… I’m in Tels btw.