I have the same one pictured (Handler 140) in your original post. It has been fantastic. I have run it time and time again probably more than the duty cycle its rated for and it has never given me any trouble. I have used it both with and without gas (flux wire) and it runs great. I also own a P&H 300 amp TIG machine and I have not used the TIG at all since I bought the Hobart. As a matter of fact the Hobart comes with a Miller torch right out of the box.
What's that tell you. All four heat ranges are evenly spaced. I then adjust the wire speed a bit to vary the heat. The machine is so easy to flip on and go for all the little jobs up to 1/4". I bought mine on special from Northern Tool for $459 and it included the cart, wire, gloves, MIG pliers and tip paste.
Stick with the 110v model for portability.