I have to say right away that I am an amateur welder, not a professional. So this is just my opinion. I've been using 2lb spools for about a year and have decided to go with a 10lb spool so I don't have to change spools as often. When I changed I could never get the correct wire speed. It squirts and makes a pretty big mess. But at least the seams are tight. I think I'll change again and see what happens.