2009 Mac Pro,new SSD for PT HD 12, Mountain Lion or Yosemite?

Hi Guys,

I Have a 2009 Mac Pro running HDX, PT 11.1.3 on mountain lion.
Just bought a new SSD to install PT HD 12.
Wondering if I should stay on mountain lion or just go for Yosemite.
Any opnions?

Thanks in advance.

2009 Mac Pro,new SSD for PT HD 12, Mountain Lion or Yosemite?