Positive camber creates torque that reduces AoA. This is why you get frontstalls. It also allows for more depower. Negative camber creates torque that increases AoA. This reduces depower but creates stability because the kite can balance excess force against the lines, any forces that would collapse the kite first must over come this force against the lines.
Both high camber and low camber can sit deep in the window. Lower camber is always more stable. What you observe with higher camber sitting deeper is the fact that the highest states of mixer pulled camber are at high AoA and as such sit deeper in the window. It's the AoA not the camber that does this. If you had high camber at lower AoA the kite would never sustain flight as it would only collapse.
The main advantage of higher camber is lift, this is simply described in the kiting world as grunt, pull, pop, low end, etc. The disadvantage is drag described as, bad float, hangtime, upwind, point,, and poor stability described as "what the f*** is wrong with this kite".
Higher camber can also be faster, lift equals speed. Though I have read the opposite can apply too.
Foil kites have the nifty feature that they can easily change camber with some AoA increase. This can be changed as a setting on the kite, as a function of the mixer ( non linear bridle attachment/ mixer ratios and things like WAC and Diablo lines), or with a trim on special bars. Camber increase can offer so much lift increase ( almost double) that water starting in light wind should nearly never be a problem, 3 knots is quite possible. As to controlling the kite or riding upwind that is another matter