I think if you're looking at a trainer for sports, then it's preferable to have someone's who has "been there and done it"... obviously there are exceptions... Arsene Wenger and Arrigo Sacchi the popular examples in football...
I'm pretty much against a lot of the whole PT culture... you appear to basically join up to a course to be a PT, sometimes the course is affiliated and ran by a chain of gyms, effectively meaning you're paying a fee for potential employment there.
I suppose what pisses me off is seeing a facebook friend who's name is "***** ******* PT" and she has absolutely no fitness experience outside having done the compulsory course. I'm not saying I, or anyone else in a similar position, should get special treatment, but i was fortunate enough to compete professionally in one sport, and earn a county vest in another, yet i'd not even be allowed to press the start button on a treadmill for a "client" because i'd be deemed unqualified... i understand there has to be some qualifications but surely there's some middle ground.
I guess this is most frustrating for the genuine-article personal trainers... they get lumped in with the idiots that come out of the chain gym system.
I knew a guy in a previous job. He was paying a PT (who i also knew) to schedule his training and diet... the PT was allowing him to eat McDonalds which doesn't really seem like good advice to be paying for. Mind you the PT quit our football team in a huff because the manager wouldn't give him a wake-up alarm call on a sunday morning, so he was a bit of a helmet anyway...