I've dabbled but not much more. My initial findings were:-
I liked the separation of concerns but I fell that's quite easy to achieve by applying a bit of discipline when using "conventional" code so I'm not sure how big a win that was for me. That said, if I had a team of developers on it I could see that it might help maintain good practices among some of the loose cannons
What I didn't like was the lack of a Visual Designer. I really come from a WinForms background so maybe this wouldn't be such a culture shear for more webby folks but for me it made things quite awkward when trying to design my screens.

I'm with Szlamany in that I like being in touch with the sql statements - again, I think this comes from the fact that my background has been very sql orientated, folks who are less sql orientated might love it - and I didn't like that all the tutorials seemed to be geared towards using auto generated Entity Framework code but I found I was able to start replacing that stuff with my own sql code before I moved onto other projects. I didn't take that very far though and might have run into problems if I'd been doing more than just mucking about.