First question is do you really need 4k? Because if you really need it now, you’ll be needing 8k in a years time and 16k 18 months later.
1080p is plenty good enough for the vast majority of applications with the added advantage that more than 0.2% of your audience can actually view it in the actual res that it was shot in.
4k just adds time and cost to the whole production process and then it is shown in 1080p to the vast majority of viewers.
Shooting RAW 4k sounds great but it needs a fairly serious computer to colour correct and then edit.
This was my conclusion too. I was contemplating a second hand gh4, or Samsung NX500, and so on but concluded my Macbook Pro would struggle to edit the footage and I’d probably need to look at a new laptop, or at least more ram and external storage.
I’m getting an A6000 as the 1080p video seems of high enough quality for enthusiast use, and it still has manual control over most video settings. If I was going up in budget then I’d be going for the Sony A7S.