I have a totally different opinion and experience than some in this thread...
Namely that in onshore you need a kite that flies further forward, turns on a dime easily and depowered, and loads of depower.
Totally opposite to the "deep sitting" grunty kites like the Kahoona which is not good for onshore waves IMO.
If fully side or side-offshore, you can park the kite and ride ("surf") - thus here the Kahoona or Wainmans or similar "thick" deep sitting grunty kites can work well - but NOT in onshore.
In more onshore you want a kite that can be flicked around easy with one hand back and fourth (most kites can though), and fly forward so depowering and you can ride really high up into the wave without getting dragged off your board, for an unrestricted free cutback.
Drift is always good, but actually of less concern when more onshore and you ride aggressively with the kite low and back and fourth
The other advantage of a kite that flies forward and can be backstalled, is that you can position it WHEREEVER you want in the window, pull in and fly it back deep, or push out and let it fly far forward for a free cutback - it is a win win when you know how to fly a kite
Whereas the deep sitting more grunty kites only got one gear unfortunately, easy for side-offshore park and ride, but not good for a dynamic ride in side-onshore, and powerspike on demand does not exist