My new boil kettle is an aluminium keg. I specifically targeted an Al keg (kroenenburg) because the metal is easier to cut/drill than stainless, and I have really cheap and nasty power tools.
I went the weldless spigot option and so didn't have to worry about getting a TIG or farming the job out to someone else.
The keg seems to be "lined" with something, but knowing the fairly extreme conditions that kegs experience when they are being washed at a brewery, the lining is both heat and caustic/detergent proof with out a doubt. Might just want to be careful about scratching chunks of it into your beer if you use a metal spoon. On the plus side, the stuff seems to have something in common with teflon. After use the kettle cleaned up spotlessly using just dish washing liquid and a rag.
It has one quite nice APA brewed in it so far. I have drunk about 3/4s of the keg and my legs haven't fallen off yet, so I say go for it.
