I have the Hobart 135 (before the 140). All an all very similar. I have used it to weld a 1000 things and would do it all over again.
In a word about duty cycle, if you exceed duty cycle it means you are operating the machine beyond what it is intended and if you melt it, the manufacturer may not be so kind to repair your machine.
Some time AFTER you exceed the "Rated" duty cycle, if you continue to weld, it will heat up and trigger a breaker.
I can tell you welding plows, tractors and many things I should have never been welding, for the duration I was welding, that MY Hobart 135 clicks off, till it cools and has caused no damage. I have exceeded this many times doing extensive heavy welding which I surely could use a larger machine for.
I don't think Hobart would support my welder for how I have treated it but it has more then stood up to my abuse and paid for itself a 100x over.
Not bad I don't think for a low budget machine.