This is a GREAT camera, however, the lens selection really stunts the possibilities for professionals.
It is fantastic for video, especially when used with prime lenses.
As Tony Northrup said, "It's a jack of all trades and a master of none." Really, if you were to buy all the best lenses for it, you still can't specialize with this camera at the moment. Other than that, it's got all the bells and whistles and I find it very easy to use and learn about.
For people with large hands, the camera may feel small. The grip is less 'chunky' than that of non-mirrorless cameras.