I genuinely prefer Mission Control for a variety of reasons, one of which being that it makes Spaces more accessible.
That said, it needs a number of minor tweaks, which Apple so far has shown no willingness to spend time on. Things like a quick way to switch from all-windows to application-windows view so we can expand the grouped windows in a useful way; or even just LaunchPad style display of grouped windows as if they were a folder.
It needs work, but IMO it's the better solution overall, it just shouldn't have been released in its current state; it's like no-one with a real workflow actually tried using it during development.
I agree that it does need quite a few tweaks and feature additions.
Overall, once they add some of these features and refine it a bit further, I think that Mission Control will be the better solution in the long run.