I'm on EPTAs GS course just now and im hugely impressed by them, I don't know anything about OFTs course so I can only give you a biast opinion. EPTAs a great choice, great instructors and its great value for money! IMO Your safe choice is EPTA, your riskier choice is OFT...try get some opinions from past/current students at OFT...
I'm one who considers UK training to be of a higher standard and my feelings about EPTAs groundschool strengthens my opinion.