Actually, mission control is a giant step back. Spaces prior to Lion were actually more useful and usable. Now they have turned to a gimmick to impress the clueless in the apple store. This is one of the many reasons I have not updated my macs to Lion, and if they continue this way I may just install Ubuntu on them.
I'm not clueless (I'm a CS graduate, I've cut my teeth on Sun OS) and I find it more useful than Spaces. YMMV, but when you assume you make an ass out of you and me.
I never said you are clueless, but I have been using OS X for a while now and it seems ever since iOS and massive iPhone uptake Apple has modified their OS design to dazzle rather than actually do work. They often take good ideas and concepts out of the OS and put something in that feels like a hindrance and step backwards to users who depended on the functionality and behaviour.
There are features of Mission Control that are impressive (full screening certain applications creates a new Desktop, for example) but I'd consider integrating Dashboard into the mix to be something one might consider the "dumbing down" of Spaces.