I have upgraded from A7 Pro to A8 Pro.
My A7 project works in A8, the big difference is mainly the physics engine changed from ODE to PhysX
I haven't use any physics in my prototype so I cannot tell the difference but tried some physics demo and found the demos are really cool.
The WED/MED editor toolbar icons look better, GED version same as A7.
It is still a good engine for Windows, no royalty, no subscription, I wonder why it didn't keep developing, particular for mobile platform.