This is a reread for me, but one with a long gap between readings. I remember, for example, thinking how right Jones had gotten the details of the convention she's describing the first time I'd read it. But the first time I'd read it, I didn't have so many British friends, so I didn't have the context to know how even more right it was for British conventions. I haven't ever used the closing ceremonies scene from Deep Secret as a Why I Don't Mostly Go To Closing Ceremonies shorthand, but I could. Because the people randomly singing and being annoying and the guest of honor's speech going the same places his panels have gone that aren't the interesting places and...yeah. The thing is, the places this book goes about conventions are both the good things and the bad. There is a Sharyn McCrumb book that's set at a convention that just set my teeth on edge, because it only had the ridiculous/stupid things and not the good ones, as far as I could stand to read. And this is not that.
It's also not all conventions all the time. There's a great deal of cross-world magic plot, people making assumptions they get overturned, people growing into themselves at various ages, and whether or not you are suited for vet med. It's a fun book. It's definitely worth a reread. If you don't go to conventions, it might be an introduction to the hijinks people get up to there (albeit in highly British form; other countries' mileage varying etc.). If you do, you'll recognize quite a bit amidst the Intentions and workings. And you'll know exactly which of your friends to eye suspiciously as a possible Zinka.
(It's Elise. Just FYI.)