Let's back up a bit...
First of all, I doubt that any of us is qualified to assess your needs as a framer. Perhaps one or another of us would benefit more from the hinging class, but that doesn't necessarily make it true for you.
There's no way we could tell you which class is "better" for you. In terms of quality of the presentation, I guess it's a toss-up. Both are good and useful classes.
Second, Jim Miller doesn't teach any matting classes, but John Ranes is teaching one on Thursday. I'm sure that other guy is honored to be confused with Mr. Ranes.
Mat cutting is a fundamental requirement for good framing, so if you could use some new tricks & techniques for mat cutting, John Ranes's class is among the best available anywhere. You probably will not find that kind of class anywhere other than the two or three major trade shows annually, where the manufacturers can justify bringing in the matcutters, accessories, and supplies for all of the students to use. It's a hands-on thing, you know.
If you are familiar with all aspects of mat cutting, then take David Lantrip's hinging class. I haven't seen it, but I know him to be a good and knowledgeable framer. Unlike major mat cutting classes, hinging classes are often available at smaller venues, such as distributor events and PPFA meetings, as well as the major shows.
Don't forget the Omni Bar Brawl on Friday, and the Grumble dinner on Saturday.