I'm still using v6.60 but I decided (again) to give v7 a try so I installed v7.5.
I noticed immediately that the graphics engine is much slower.
Panning (keeping the middle mouse button pressed and moving the mouse) is super smooth with v6.60.
With v7.5 it's sluggish. I'm back to v6.60.
I hope you can fix this.
Kind Regards.