Mig is nice, Tig is prettier! Depending on material thickness Tig might be better too, especially with aluminum. We've welded some pretty thick aluminum with Tig, but we also used a torch to pre-heat the aluminum.
I have a 50' Python for my Powermig 300. It does a really nice job with aluminum. It takes a bit to get use to tho, but once you get the hang of it, it's really sweet. A whole lot faster too!
