I need some help making up my mind about a new welder purchase. It comes down to a new Thunderbolt XL, a new Millermatic DVI, or a good used gas powered AC/DC machine (10Kv and Canox is the brand I believe). With the Millermatic, I could sell the old Miller Cricket XL I have now, but either of the other two and I'd keep it. I'm looking for a machine for hobby/light fabrication type work, not to make a living with but maybe a few extra dollars now and then. The Cricket XL has served me well for the 15+ years I've owned it despite two or three blown circuit boards, a result of misuse by me and a few guys around the garage! But I'm not in the autobody trade anymore and I've been thinking of getting serious (more serious!) about welding. The Cricket is just not suited to thicker materials and longer welds.

Any thoughts?