The DASH seems to work about 90% of the time on clean and thin sheet that has a uniform color and finish roughness.
However, if the plate is rusty at all, or has dark and light spots, or rough spots, or pretty much anything other than pristine metal, the DASH doesn't function at all. Expect a crash ~99% of the time.
Basically, I've only had mine for a few months, and I've come to the conclusion that it's not worth the trouble on anything heavy enough or flat enough to touch off like normal.
When it works, it's cool, but it causes a LOT of crashes, and it has to be calibrated literally for every single sheet you use it on.
I dunno, seems like an ohmic sensor would have been a hell of a lot cheaper to implement, but I had no idea what that even was when I ordered this thing.
Bottom line, it costs a lot of money, and I curse at it a lot more than I praise it. Maybe with time I will find it pays for itself, but the only way that is going to happen is if it stops crashing so damned much. Bad enough that it costs an arm and a leg, but on top of that, it's smoked at least four nozzles all by itself, and for inexplicable reasons.
If I could sort out the problem, I would fix it, but the issues are so transient, I can't replicate them well enough to figure out how to tune them out.
Also, the self calibration thing is not real accurate. What it does, is it uses the laser to look at the plate while it lowers the torch. When the torch touches down, the laser records the reading and stores it as the offset height. I have calibrated it a half dozen times in a row in the exact same spot on a piece of 1/4" plate, and every single time it came back with a different offset. The variance was as much as 1/4", which is why the damned thing crashes into the sheet so much. One calibration it will be fine, the next it's a 1/4" lower, and hits the plate when it goes to pierce.
It's enough to make a man scream and throw ****, believe me.
I was doing test cuts today, and I had to turn the DASH totally off to get the thing to make a cut at all on a piece of 1/4" HR that had been outside (IE covered in rust).
It would calibrate, check the height, then mash the nozzle into the plate, fire the plasma, smoke the tip, and then drag the torch along the surface until the collision detector tripped the e-stop.
If you always work in new thin material that is stored inside and not covered in crud, you'll probably get a lot of use out of one.
If you always work in 11ga and thicker stuff, I wouldn't spend the money.