Been using the spools of HF F-C i bought at the same time I ordered my welder from them. Switched last night to some Lincoln .030 wire my pops got me for x-mas. WOW, what a difference! It burns MUCH hotter and faster. I probably picked up 1/32 to a 1/16 of penetrating ability just with the wire switch. It also smells different when it burns...different flux formula maybe?
Anycase, if anybody is using a smaller welder like I am and is using a cheap brand wire...you can get better penetration and better welds if you switch wires, but you don't have to take my word for it. Head down to Home Depot, grab a small spool of Lincoln wire, and see for yourself.