The tilting you see if from my horribly tilting assembly I built for my AmeriBrade. I was going to cut some angle iron as a 3rd leg to stabilize it, I am just going to buy their tilting assembly instead of redoing mine now that I have the surface grinder!
That grinder (toobinator) is easy to put together with basic welding skills, I did it with parts (wheels and platen) from another grinder maker. It is literally 50 bucks or less in new steel for frame and two arms.
I see the grinder and kit on USA knife maker but I can't seem to find any reviews on it. Is it just so new that there aren't many out yet?
My KMG style belt grinder and the new disc grinder sit next to each other on the bench and both run off the same VFD (alternately - not at the same time) I designed and built a swiveling frame to allow the grinder to sit in one fixed position on the bench but still allow me to access both discs from the front.
Flipping the grinder onto it's side is the easy button for 90 degree angles, and particularly on an inside radius. Being able to lay your blade flat on a work rest and bump it up against a contact wheel running left/right makes it much easier to grind an inside radius and keep the grinds square to the blade.
A comment on the compression vs tension springs. The first grinder I built was a pretty close copy of the KMG clone with tension spring. Tracking was so-so. For whatever reason, I never fully understood why, but after I changed to compression the tracking improved. It might be nothing more than the amount of tension that was put on the belt.