I also noticed the GUI is now slow, with significant delay and very high CPU usage (Xorg process and leonArdo). I disabled graphics acceleration on my desktop because I want to dedicate the GPU power to mining, however on the previous version it was performing good enough.
What OS flavour are you using?
I'm using Ubuntu Mate 17.04, fully updated. As I mentioned I'm running my desktop without graphics acceleration (window manager = Marco/no compositor), to dedicate GPU power to hashing, but once you fix the core dump, I can test different window managers (Marco with software or GPU compositor, and Compiz) to see if that's specific to my current setup. PM me if you'd like help to test this or other things on the Linux side, as I have a good experience with this OS and will be glad to help.
Bro can ask you: I'm running a VPS on ubuntu 16.04. What the the recommended way to remote connect to the VPS from Macbook pro? (I can ssh to the VPS). Currently I'm accessing using KVM from browser but seem it's not the best option. (My Ubuntu currently running GNOME)
help is much appreciate. thanks.