It really comes down to the scopecam. I agree with Gepard. If you dont have those two then filming for anything other than yourself is pointless. If you go with a headcam then you can only ID things about 10m in front of you. If you go with a guncam you get very limited video and the same issues you get with a headcam. If you go scopecam only you get good shots, but still the limited video of a guncam. I say you really need both a head/bodycam and a scopecam to make any worthwhile videos.
Duff, I agree it can be easy to switch a cam between gun and head, but you still have the same lack of zoom. For the most part, any youtube video I watch that doesnt have a scopecam of some sort I will quit within a few seconds, as the guy could be shooting at a bush for all the view knows. Hell, at this point I use three cameras minimum, and sometimes up to 5 if I want all the angles. Sure, its expensive, but thats life. I would reccommend getting a cheap GoPro clone off whatever Chinese site, and a mobius with a magnified lens. It'll cost you less than a single GoPro, and while it wont last you as long as a GoPro, nor will the quality be as good, you don't need 4k for airsoft, and itll allow you to get both angles which are basically a necessity for good airsoft videos. To go even cheaper, get a 3x magnifier or a cheap sniper scope and use that in conjunction with your GoPro/clone to get scopecam footage.
The one exception to this rule is if you are playing CQB. I did not use anything other than a single GoPro when I played at The Mall or the killhouse at Combat City, but besides that you need the scopecam.
