Was wondering myself about it...
So since we have to justify ourselves now when thinking about buying a gadget: wife wants to buy me something for birthday, but can't ask for an expensive new kite or board. Already got GoPro, harness, glasses, impact vest, helmet, well, all the noob's gadgets, since I've been kiting for a few years, but not consistently... So all that's missing is one of these devices... Am I allowed to even think about that, even if my STYLE is wayyyyy too awful to look at? ;p
Anyway, my 2 cents: since I can't even jump above 7m (I know because I tried the Trace...), I plan on working on that on my next trip, so I feel that one of these toys will allow me to see my progress as I try different timing, etc (but then, I may be delusional).
On paper,
Xensr would be the way to go: GPS, so after session, you can replay where you did that sweet jump, and even see how the board moved in the space (well, supposedly...), and during the session, you can see immediately how was the jump you just did (with the aid of smartwatch)... BUT seeing all the problems with version 1 and 2, and the fact that they seem to have a ton of unsatisfied customers waiting for their replacement device for months now, you would indeed have to trust your golden luck to order one, if you even could do so. Looks like you cannot even order it in Europe, as distributors got fed up of being in the middle of the mess maybe... Really sad: for me it was really the way to go.
Trace: GPS check, jumps data, OK, but you have to wait the end of session to replay it (no direct feedback). Not many people using it.
Piq: now, this seems not too bad, you can see your last height... between your legs, and some are complaining that with water drops, not such an easy task. No GPS, community seems to be growing, best candidate maybe as of now.
Woo: no GPS, but most people using it, have to wait for end of session... There is this "freestyle" mode ( not for me yet: STYLE is lacking...) BUT, a single picture (
http://www.kiteforum.com/viewtopic.php?t=2397007) can make us wonder if we can expect an instant feedback (hopefully on android wear too), and since swartwatchs usually have GPS, we might even have a session map, like Xensr and Trace...
So here I am, waiting for someone to make the perfect gadget. Until then, I think I'm going to work on my STYLE without it...
On a side note, the Revl Arc seems like quite a let-down, and Quark not ready yet, so I may have to ask for a new pump, quite disapointing I must say, unless you have an idea?