Well, Sylvan is pretty shallow and Pine Lake has a bit of a weed problem. Cold Lake's name probably speaks for itself (can't confirm that myself)....
While water skiing is possible in those places, it's not really that good when compared with the lakes of our provincial bretheren. But it's all subjective, so I'm not doubting you have a good time in those places.
Mara Lake: actually a southern arm of the Shuswap, and probably the best for skiing because it's smaller (less choppy and slightly warmer). Good mention.