I was in anaconda yesterday & they are chucking out the jetboil companion cups for $35 which is better than the $55-60 from eBay. It's just the cup with the flux ring on its own but handy for a second stove.
The Jetboil gets great reviews everywhere, but VERY expensive for the basic unit and for any accessories. I wouldn't mind one, but probably will only get one if someone buys one as a gift. I'm tight as a fish's you-know-what when it comes to stuff I'm not sure I really need. My $20 Companion works great and with the attachment for the cheap 'pressure pack shape' canisters you can buy for $1.50 each it's really cheap to run. I'm not that impatient that I can't wait 3 minutes to boil a cup of coffee or tea, and for a cheapie it is ultra reliable and easy to adjust the flame. But I definitely wouldn't think about using it aboard my yak. I'd rather pack a thermos .
I have had mine for about 5 years now, picked it up a good priced package deal from the States. The fry pan isnt much chop, the non stick surface isnt. Although its fast cooking and its cool how the plate clips on to make it more compact. I'd be looking for a better fry pan. The mug is great, fast boiling and stays hot for a long time. Dont have too much trouble adjusting the temp, its a little fiddly. Not sure how it would handle the salt water out on the kayak. Id make sure to give it a good clean down after each trip.
The gas bottles are nice and compact, but only last a couple of nights. I usually take a larger spare. I have a very compact gas light attachment, but prefer a led light. The gas lights burn yellow and aren't very bright.