Well it looks like the THC is just no good, if i tune it for slow cuts it works well, but could never manage a cut at 3300mm/min, pretty certain if up the tuning to go faster it will bunny-hop on slow cuts due to overcompensating. :(

Anyone recommend a THC ?

I have tried contacting CandCNC but had no response yet.

I had this reply from Proma....

"THC 150 has about 150ms (0,1 - 0,15s ) processing time, o don't sure what many time need mach for reaction.
total time isn't very well for it. I think that better is use model SD (step dir) or full system MD+DV. both systems works alone (without software) and total delay time is about 70-80ms - for high speed still it's not very fast but better that compact THC."

Sounds like speed is not their thing?