If you are mainly shooting landscapes andportraits, the 5D Mk II is what you want. It's got better IQ and is better in low light. The 7D has a better AF system and the 1.6x for the focal length is much better for sports, birds in flight, and wildlife.


I would say that the 5D Mk II is what would work better for you.


Regarding your questions:


You can take stills with the 5D Mk II. There is a slight discontinuity in the video as the frame is taken.


I like the image quality of the 5D Mk II better. In marginal lighting conditions, there is quite a bit more noise in the 7D shots in the shadow areas. I can't tell you how much better the 5D Mk II is because I haven't done much low light shooting lately. I haven't done much videos with either body but in low light conditions, the 5D Mk II should be better with the FF sensor.