They are awesome. We got them when they forst came out and they had some parts issued but miller resolved them very quickly. I tried to blow one up and it didn't get it done. High school kids are experts in breaking stuff and so far they have held up pretty good. They pulse gmaw like a champ. Stick is a bit tricky at times. I like to hold a long arc length when I light uo to let everything warm up. The machine does not want to maintain a very long ark before either cuts out for saftey.How are the 255's working out for you in the school? Have one in my home shop and been a very good welder so far and really like the pulse function. The XR Aluma Pro gun does a nice job on aluminum.
I'd love one at home for the versatility.