Compared to RED camera for example, an HDSLR production can come in at half to a third of the price. Because of the weight of the camera, it’s sensitivity to light, and the support systems– you don’t need as large of a crew and it’s also significantly faster to set up and take down (again related to weight and size). And, it can look better in certain instances. These cameras shoot on a full frame sensor and they are astonishing in low light. Nothing comes close to it in low light. Another key factor is that these cameras can better take advantage of available light like few other cameras can – this means that you don’t necessarily have to bring in cube trucks full of lighting equipment in some instances – and obviously lighting is not only a big line item in any budget – it also contributes to more than a 1/3 of production day in terms of pre-lighting etc. That being said – and this is important: there is no substitute for good lighting! These HDSLRS just allow you to get away with a LOT more.Vincent Laforet Goes Beyond The Still
And check Vincent's own post: So What Does An HDSLR Hybrid Shoot Look Like?