Thanks for the replies guys! really appreciate it.
I think I'm pretty set on the Ronin M & this has kinda confirmed things for me, I think from there I'd even spend more money on building on my current set up (more lenses, a drone etc.) before getting to 4k. As much as people & potentially clients don't notice I think us as filmmakers notice way more, I probably spend too much time watching ridiculously high res films on Vimeo & Youtube & compare my own footage to that. Anyway thanks again for the replies!