That's all I have ever used, until a deal on a thermal arc came up that was just way too good to pass up. And it will run circles arround any miller I ever touched. ( probably because the TA is brand new and the millers have all been 70's era machines)
My buddy has a miller plasma and it's nice, i would not hesitate getting one for use as a hand cutter. But it will not work on a CNC plasma cutting machine. Because it's a high frequency start machine, and it will destroy the computer.