Can I upgrade to Cube 10.5 pro from AI around Xmas for 100$ or so??? Can I expect a smoother and more glitch free experience
if I do??
You will most likely not be able to upgrade to “Cube” 
10.5 Pro around that time because, if my guess is correct, 11 will already have been released.
You really think you are going to upgrade to Pro from AI for “100$ or so”? 
I have no idea what a “smoother and more glitch free experience” means …
I was kind of joking… but lets see what happens around the new year…