Movin' around some type
The first is the ability to create custom plugins as a developer. That is so key. I love anything that resembles legos. Legos are fun and educational and you can make them do whatever you want. The ability to customize a tool like you would a lego set is something that more applications should strive for.
The second thing that rocks about Movable Type is the flexibility afforded by the tag based architecture. Now to be fair, it's not that .Text can't be updated in a similar manner but I generally feel like I don't want to go run around and play with its guts because the code is a little umm... dauntingly organized. Movable Type feels far easier to understand in comparison, but then again it's a far more mature product.
Unlike me. Who compares things to Legos.