VBox Windows 10 Host, Ubuntu 16.04 Guest Lagging and Slow

I've been running a Vbox for a while with Ubuntu 16.04 on it. The Win10 host is a laptop with plenty of power to run Vbox. I'd given the Vbox half of the ram and processing power of the host.

I use the Vbox for astronomy purposes running DS9 for blinking images.

I noticed that the interface was extremely laggy no matter what I did. Maxed out settings, installed guest additions ect. Nothing helped. I then found this article:

https://askubuntu.com/questions/651013/can-i-remove-unity-now-and-how/651088#651088

Apparently the issue is Unity, and there is no fix. After rolling back to Gnome following the instructions there, performance was fantastic.

Hopefully this helps someone else.