It depends. If you need some good looks and have time to wait rendering (MB takes a long time to render due to it's high bit depth processing - makes for good quality but SLOW render times) it's possibly a good choice. I recieved a copy free with my DVX and don't really like it; just doesn't suit my personal needs.
Truthfully, learning the MBE interface takes about as much time as learning the basics of color correction. The second is a whole lot more useful (the whole teach a man to fish thing). With presets looks like MB you end up with a product which looks like everone else's. I'm a big fan of creating unique looks for every piece.