I've never had any sort of tutor, but if I were going to choose I'd take a math tutor from this site before I got a tutor that wasn't a recent ex-student. I mean, for the level of math you're studying, I'm sure that a very high-scoring student would understand the math just as well as someone which a Math PhD. Moreover, having just gone through the system a private tutor has a fully recent experience of sitting VCAA exams and knows in detail the tips and tricks etc. I've never done any real math, but it'd be like English... You'd be pretty hard pressed to find a teacher that knew Twelve Angry Men as intricately as I do (and I don't mean to be a braggart, I'm just saying that a student will read the text a billion times and write essays on it, and do very detailed extra research etc etc etc), whereas most teachers simply don't have the time, motivation or reason to know a text as deeply as a top student might. Obviously the English teacher could probably write a better essay or has a bigger vocabulary or whatever else, but ultimately, the tutor's knowledge is just as sufficient as the teachers, but the extra experience of having just gone through the system might be invaluable.
Could be totally wrong, having never had a tutor or done any legit math, but that's my logic, anyway.