Yes indeed, I agree: quality cages are one of the most important parts on a bike. This is especially true around here, the roads are third world-ish in the spring. I'm always amazed at how many terrible designs are out there that launch bottles at the slightest bump. This is really dangerous in a group.

Stainless is a great option, but other options hold just as well if not better. Elite seems to know what they're doing. I like the Elite Custom Race cage for my road bike which cost about $20, hold securely, look cool and are basically indestructible. For mountain/cross, the ~$17 alloy Elite Gel Ciussi is my favorite. Ciussis are really tight and a bit of a pain to get a bottle out of, the tradeoff is that it's basically impossible to lose a bottle from them. Ciussis are the most commonly used cages at Paris-Roubaix for a reason.