That is not entirely true. Since the 64bit version of Cubendo can use a lot more RAM, it also uses more RAM for event handling etc. Save buffers, etc. etc. So it will run better than 32bit IF you have 8GB of RAM total (more are better).
NB! A project that was running close to memory limit in 32bit, after opened and saved in 64bit version might NEVER open in 32bit version.
Also make sure that all plugins are 64bit capable. bridge is ok for getting a project exported etc, but can’t be compared to true 64bit plugins.
Even UAD is out with 64bit plugins now.
Pål