The Blackmagic range of cameras are really aimed at film-making professionals.... typically they are not very easy to use and whilst having interchangeable lenses may appear a step-up, it introduces are new chapter of difficulty Cost ...IMHO. .
The one (you linked) is a serious camera for professionals, but it will be expensive. Clearly this is aimed at extreme sport filming,where the small size and remote controlling are hugely important. It may find situations in action-films too where the car-crash is a 1-off event, the camera-cost is of little consequence.
Typically Blackmagics will providemore filmic-quality.... but this is often a result of their ability to give wide image-grading which you process in Post. Film-makers love this;but for my money it adds little to a good story. They are as sharp as the lens you buy . . . and typically folks use fixed-focal-length Lens ( Non-Zoom) as they are filming from a Script and can move the camera between "takes". For sports the lens can suit the position and field of view.... allowing large-aperture, long-lenses to be used - but these will be very expensive pieces of glass.
A Pro-camcorder, for a smaller investment, offers far more certainly and most also have the low-contrast Option - if that's your thing.... but not of interest to Sports activities, I'm guessing.
You could try hiring one . . . .
Good Luck.