MEL can actually be surprisingly useful in modelling, at least when it comes to writing tools that help with the process. If you want to learn more about MEL, you can check out The MEL Companion: Maya Scripting for 3D Artists by David Stripinis. I picked up a copy on eBay for $3 (amazing deal for a $50 book, I think). It's really an excellent, well written guide to MEL, and it goes over the applications of MEL to the various aspects of 3D design and production. Hope this helps.