I have been using my trusty Sony Z1 for 4 years. I have a wedding video business and I am starting to do more events and online promotional work. I want to invest in a more up to date camera and have been looking at the three cameras in the title of this post. I like the shouder mount and exchangeable lens of the GY HM790. I have read that the EX1r is the best in low light situations ( which is very important for me). Taking into account lens, sensor, recording media, bit rates, dof etc.. and the work that I do what are your thoughts on the best of these cameras (or any other similar cameras)?