Hi Owen - and welcome! Yes there are plenty of Brits on the board (I'm from Newcastle but now living in Dubai) as well as lots of other nationalities.
I've been about 90% Primal for 2 months now, like you I have yo-yo dieted in the past, I had most success with Weightwatchers but was ALWAYS starving and surprise, surprise, put all the weight back on and more. I decided in June that I didn't want to moan about how I looked my whole adult life (I'm 31) and having dabbled with ancestral eating before decided to give Primal a go. As of this morning I've lost 17lbs, I have more energy and much more even energy levels, and (after a few days of carb flu) I haven't craved or missed grains or sugars anything like as much as I expected. I also have a much more positive body image and (thanks to better food and more sleep) am generally feeling happier and healthier.
I'm certainly not an expert so have found the forum really helpful, both in terms of answering my questions and just hearing about other people's experiences.
Good luck and let us know how you get on!