I've used the Ryobi MMA-160 welder for the past year and a half and although many think Ryobi is terrible, this welder is absolutely awesome. Excellent duty cycle and I have not had it overheat once during the time when I first started teaching myself to weld with this machine and I ran bead after bead, rod after rod, only pausing long enough to chip off slag and to put in a fresh rod. Definitely suitable for diy use and for contractors. Plus you cant beat the price.