Is Cubase 6.5 Artist now stable for 64bit OS?

Hi!

When I bought 6.5 Artist I was recommended to use 32bit-version because I had problems with the 64bit-version and lots of the VSTis I was using. Would anyone recommend me to swith to 64bit-version or should I stick with the 32bit-version? I have problems with Cubase not being able to allocate enough memory at the moment so I’d like to go 64bit.

C6.5 always was stable in 64 bit. It sounds like you were advised to stay 32 bit because your plug-ins were not 64 bit and they didn’t bridge well. So the answer to your question lies in whether or not your plugins have 64 bit versions now. If they haven’t changed, then you will likely have the same issues.
HTH
J.L.