I've had the PMW200 / Gates since March this year and so far it has been used for 3 stock trips and a 3-4 month shoot for a 60 min broadcast documentary.
The quality is superb straight out of the camera with no external recorders required and the Gates housing is wonderful to use. The only slight issue I have had with it for underwater use is that the PMW200 does not have component out for the external monitor so if like me you had a EM43 monitor from a previous housing then you'll only get a low res image displaying on it. Gates now have a high res HDMI monitor, but I've not had an opportunity to use that personally.
It is extremely difficult to say anything other than wonderful things about Gates. There is a very good reason why the whole broadcast industry relies on them and the PMW200 is a cracking camera. Unless anything remarkable and affordable happens in the immediate future with 4K then I'd say it is a great choice. Hope this helps!
Thank you very much, Simon.