That said, if you want to just use his mics, etc and run your UA-5 > JB3, that's fine. It doesn't mean you're a wimp, it just means you are comfortable with what you know, especially if you are drinking and don't want to be responsible for some else's expensive recorder.
I went with the UA-5 > JB3, largely to minimize the number of unknowns I had to deal with, which would reduce how much fun I was able to have at the show. I got an amazing spot, and the sound off the stage was great (e.g., you could close your eyes and hear exactly where on the stage the guitar amp was left-to-right), and I think I pulled a really nice recording. Thanks, everybody.
Aloha,
Brad