Hey Pete,
Yeah, I've got a place on both, however I'm leaning more towards COWA as its more widely accepted by universities. Do you have a place at Manchester? I didn't attend the COWA selection day personally, I had a Skype interview, but it was very similar to the Manchester one, like why do you want a place on the course, what experience do you have, have you researched universities etc..
What is your background?