Also see below for the answer to the Question : What is the gopro hero 4 black 4k video like ?
I run a Phantom 2 from DJI FPV system which is capable of full 4k professional aerial footage both photographs and video. This inspire takes things to a different level in areas that you may or may not need. I shall explore the inspire further but for now the phantom 2 has everything I need and travels well also.
What is the big advantage to the inspire ? Well for me it is the almost full control of the camera while flying. So you can tune the exposure for example or frame rate or resolution, yes it does support 4k up to 25fps so seems to be on a par with the hero 4 black from gopro. But this is adding a lot of cost to the hobbyist and I feel pushes this into the company realm. We will have to see how the production inspires turn out and maybe see what a second generation inspire brings. But in closing it is what dji do best they marry the apps and peripheral stuff to the multirotor model - its how they weave it altogether its what apple would be making if they did quad copters. I am very very happy with mine.
Answering the question on how good is the video of the gopro 4 black edition shooting at 4k in reality?
Here is a still made from 4k video with the gopro hero 4 black edition. (the image seen needs to be downloaded or inspected at the full file size it has been reduced in size to fit this blog post.)
In fact its not true 4k but UHDTV with a slightly smaller resolution of 3840 x 2160 (this was my first shock)- you may need to right click to get the image in a new browser tab to see the full size version - or download it and inspect it more closely. I do have to say that you can zoom in and take a crop at a quarter and still see a sharp image. I might be with a lot of people saying that technology has gone beyond what we can natively appreciate ! I think the value of the slow motion 1080p for action sports is worth looking at otherwise 4k might be of use for projecting a large image perhaps. Not sure..