Title says it all, has anybody used MonoGame before?
I'm especially interested in how the performance is, I know there's some commercial, shipped titles that were developed on top of it so I guess it can't be too bad performance wise but maybe somebody has some further experience with it.
I'd also be interested in usability and in how low level you can get with it as I'm coming from a C++/OpenGL background but am evaluation options for a team project with a team which is mostly inexperienced with C++ and I too would appreciate some kind of groundwork.

To round up this question, if anybody has experience with C# for game development in general (I know there's a least one person here), especially in terms of performance, I'd appreciate an opinion.