Just bought the little Hypertherm (PowerMax 30) unit and am quite happy with it. A few notes.
Thought I would run it on bottled dry nitrogen to avoid any moisture issues. Runs nice, but REALLY used up the nitrogen quickly. Like 20 minutes. Switched over to shop air (with a separate filter/dryer, and haven't noticed any difference in the cut quality.
These cutters make 3 types of cuts. Quality, not so quality, and sever - based on the thickness of the material. This little unit will sever 1/2 steel, but at a speed of 5 inches per minute. So, hold your hand out and then move it one inch while counting 12 seconds - pretty slow. I actually get a little faster than that cut on 1/2, with a finish still better than a torch.
Absolutely walks through 1/4 inch. Quick and clean.
I recommend a guide for any cutting operation. The Kerf is pretty thin, and any wandering of the torch head will show up. (My first few straight cuts wound up looking like a termite track. Putting down a straight edge solved the problem.)
Nice to use. Turn it on and cut away. Much easier than getting out the torch (which I still have and use for any really thick stuff).
FWIW
Thanks,
Jim.