The difference is huge, being able to max out graphical settings, but it still slutters in Vam.
This is so true! I had the same experience with my new water cooled 6900xt. That is what I always try to say: with a new monster GPU you can use 200% supersampling aso, but this would not stop VaM from stuttering in VR. Even a new CPU with new board and fast RAM did a somewhat visible difference here and there, but VaM still stutters in VR...
In this regard it was a disappointment (which I had expected, but...)
The biggest difference I have got was when I bought a bigger SSD and moved VaM to this coming from an HDD.
Like you said: if the stuttering and fps drops are your main issue, for instance if you have two persons with high physics hair and clothes with three light sources, or if it is the slow responding time in the user menus or the loading time, I bet this simply can't be helped by buying new and expensive hardware. Maybe wait till VaM 2.x before you do this!
RAM issues: personally, I am still at 16 GB RAM. I know the memory issue when scrolling through many different clothes very well, too. But this has got much (!) better since the last versions. Those crashes to desktop are very rare now. If you speak of 15 minutes, this is maybe the same for me even with only 16 GB. I am not completely sure if 64 GB would do that much difference?
As you may know, there is a button in the person's main tab for clearing the RAM, exactly as a workaround for this issue. Just click on this button every 5-10 minutes, when doing a longer dress-up session, until we will get the new VaM 2.x.