I am running the same hardware as Gary is. I'm running that gun file at 100 in/min with an accel of 15 and a CV Tol of 0.10. Velocity is 850.2 X and Y. Any more than 15 on the acell and I get too much (for lack of a better term) after jiggle from the jerk in the Y direction.
The table is solid enough, it's the carriages. I've done what I can for reinforcing them short of welding the whole thing up, but I'd rather build a completely new gantry/carriage than have some local sod buster welder come in and make a mess of it.
I can get as high as 23-26 in Quantum (maybe higher if rapids were under the same control as feeds), but files like this one won't run for me in Quantum (apparently due to the small segments/arcs).