I really miss the simplicity of having "Marketing Activities | Design Studio | Lead Database | Analytics" across the top.
Switching between them (which we do all the time in Marketo) now requires a click on the magic ball thingy (the round Marketo ball), scroll to find the right location, then another click to select, instead of just a single click the old way. It's so much less efficient now.
It seems like there's plenty of room in the very top purple bar to add that "legacy" navigation back in.