Nope, I didn't like it. Mind you I intensely dislike James Corden. Whenever I see him on a chat show, or presenting something his main line of humour is to jump up and down shouting. Plus I'm not that a big fan of Gavin and Stacey.
I think after reading all the reviews and knowing its meant to be crap, my expectation will be so low that I'll enjoy it when I see it (on tv in a couple of years).
I saw it today, enjoyed it I think you have to be a fan of James & Mat to see it, if you like their sketch show and like their humour then you would like it. I wouldnt recommend the film for people who dont like them/their humour.