It is a good camera, but if you are wanting a better portrait camera I would go full frame I am very happy with my 6D and the prices have been coming down due to new models being released with more expansive video and focus features.
It's not as bad as some of the other canon models on the market but not the absolute best out there. I am happy with the results I get from it in low light. I would also suggest a ring or hot shoe flash if you are shooting people or anything moving