I rode the Hadlow Pro (11/9/7m) all last year, and have used the Hadlow Id a lot (12/10m) this year, whilst still using the small sizes of the hadlow pro.
If someone were to come to me, and ask which kite is for them, my answer would be as follows:
If you want a kite with a good wind range, something you can boost easily with, which is stable and easy to fly, and are possibly unhooking, but perhaps not doing (or working towards) more complex tricks like airpasses and mobes yet. Then the Id is the kite of choice.
If however, you are either air-passing already, or looking to progress onto that soon, and want a kite with a bit less bar pressure than the Id, explosive pop, more slack, improved direct feel & more power in the loops, then go for the Hadlow Pro.
There is quite a bit of overlap between the two kites though. If either of the descriptions above don't shout out at you, then you'll likely be fine with either kite
I ride in the north east of England, and the wind is *ALWAYS* gusty. I have no problem using the HPro, but I am used to it.
I know you don't want to change kites as the wind changes, but to be honest you have to, if you want to unhook with confidence. Even if a kite has a huge windrange, you wouldn't want to unhook with it when its outside of its optimum range.
I'm sure you've probably seen all these, but just in case you haven't:
http://www.forcesix.com/hadlow-id-and-h ... -back.html
http://www.forcesix.com/2011-flexifoil- ... eview.html
http://www.forcesix.com/2012-flexifoil- ... eview.html
For what its worth, I'm now using the Hadlow pro again full time, but i have improved a lot this year, and I'm seeing the benefits of using it whilst air-passing.