I've been unimpressed with the two choices I've seen. As sad as it is to say, Sorcerer and Savant has the best treatment of fantasy mechs with its warstriders. They fit a nice happy medium; they're treated, effectively, as suits of armor, but lots and lots bigger.
IKCG, well, I haven't looked enough at it, but I don't recall their mecha actually having pilots, just wizards who hung out nearby.
DragonMech, while it might be nice, I have conceptual issues with. I'm not entirely sure how a giant walking city is useful, or even doable, and exactly how it can dodge chunks of falling moon. While it may be the best mecha system for fantasy ever, I'm not going to touch it with a ten-foot pole.
Brad