What Both defer and gateman said above..
but compared to a punter..
you both know and understand wind and how to read it.
UBK& Understand board and balance using the wind
URB competent to go out beyond your depth without getting phased..
So the main differences are..
How the power is transmitted to the board it is less complex
Hhow you capture the power, the kite is initially more complex but once you start including Gybes etc kite is way less complex...
SStarts.. well if u use a floater and haul up..mast that's no fun if you standing start one foot on board that's about same as kite start.
A stand out difference is the ability to start and stop power delivery.
Windsurfing is way more straightforward..
Kite no drop mast and relax. The kite is active from launch till landing there is no off. But. It is obviously not a major issue a lot of people kite.
This is where kites take getting used to.. it is also where very rapid change occurred in design some10 plus years back.. the target being safety.. so kites have a complete setup you will find new.. but capable of being understood fairly quickly due to knowledge of wind/power development from sail. So the way to checkout is that land based handling.
summary.(joke

). in the learning phase...kite considerably less muscle required.
kite control has no easy comparison to windsurfing you have to learn it windsurfing is a lot easier to learn sail movement balance and power delivery but once you are moving on a board I feel kiting is easier.. getting that balance on a windsurfer especially near the top or bottom end of the sail's range is harder and requires more physical power.
windsurfer likely to get earlier runs on the board as a learner the board floats and once balanced you just zip so more leeway for error..
Kite.. building that solid familiarity once you expect to be able to ride the board each session is easier to windsurfing especially since the first board type you use is symmetrical so go to left or go to right is basically the same.
There is no free lunch but you are well ahead of a rookie..
Both crews are generally great helpful.. so if you want wind power and portability give it a crack...
cheers
AP. (In dry dock for a number of weeks after bike stack so time to burn

)