We're all "edge" people here & have the zig-zag pan & it's great! Too bad DD moved out & since the pan was hers, she took it with her. Waaaaaaaaaaah!
However, when I saw the commercial for this pan with the insert I had to get it for her because she likes to take treats to work. It will be easy to serve because the rack turns into a holder for the pan which pops the brownies up for easy serving!
I got them from QVC because a lid was also included, although I'm waiting for replacement lids. I got an email from QVC saying the lid wasn't quite right & replacements were being sent within a certain period of time.
PP's are right, too; plastic knives are the only thing that cuts warm (or cool) brownies decently. I never thought of using a muffin tin for brownies but do use them for mini meatloaves!