Everyone has their own opinion. Generally Seats are considered "uncool" so cop a bit of negativity, pehaps unfairly - apart from the nappy look.
I normally use a waist, but have tried a seat on occasion.
the main difference is that a seat will not ride up as it is anchored via the leg straps. If properly fitted it should not actually be uncomfortable or squash (or pleasure
) sensitive areas. As mentioned this is a big bonus when learning as it keep your bar within reach when the kite is overhead, and the pull from the kite stays low at your hips. Many girls like the seats, but I might suggest it is more to do with not having a waist crush thier boobs and keeping a low centre of gravity than a seat being overly pleasurable. Girls tend not to worry too much about what guys think are or aren't cool either.
The main drawback in a seat and probably the main reason waists are more prevelant (ignoring coolness) is that they do not slide sideways. Riding toeside or in the waves or even in normal riding it can be much more flexible and comfortable having the waist harness slide around a bit so the pull from the kite is on your side, not still in front of you trying to twist your whole body around.
I have heard good things about the boardshort harnesses, but have not tried them. They remove the uncool tag of seaties and even up it a bit as it looks like you are not wearing a harness at all!! You can wear them on the outside of your wettie too and have an excuse to do so when the polies laugh at you!!
