EZ Flap,
Lets not equate a low gross weight, which the Kitfox II has, with light weight use! ANY aircraft consistantly flown over gross, poorly maintained, too fast etc, will suffer, as you mention in the cert plane with the sloppy joints. There has NEVER been a structural collapse of a Kitfox/Avid type wing (I'm going out on a limb here, feel free to correct me if I'm wrong....I'm just repeating what I've heard), and considering the fleet hours, and wide range of builder skills and piloting skills, thats saying a lot! The epoxy is not JB WELD, (although...JB is GREAT stuff!) and yes it is indeed designed for its use, bumping it in a hanger will break the plywood rib before the glue joint gives way. Many of the type have of course crashed, they hold up as well as can be expected, the glue joints are never the problem. You make many good points, and if you meant don't put 40 gallons (somehow) of fuel, and 2 250 lber's, and (somehow 200 lbs of gear) and operate out of a plowed field I fully agree. I thrashed my Kitfox 1 ('88 model) pretty good for 650 hrs, its still flying, I just USED it not ABUSED it. Although I am not flying the type anymore, the lastest Highlander models illustrate they are solid, but "lightweight", aircraft. If you meant certified designs can consistantly operate over their design limits and suffer fewer complications then a Kitfox type homebuilt, you are on shakey ground....
I too, love the T-craft, and agree it may be a better bang for the buck, I made 3 K when I sold mine, that owner made money when she sold it, as did the next owner (this in 9 years), then I got to ferry it up to Bozeman where it is still, no doubt providing cheap flying.
OK, I won't mention the T-craft...
When yuou go to see the Kitfox again, check the glue joints between the aluminum tube "spars" and the wood ribs. They are glued together with some kind of JB Weld stuff. Problem is, you cannot bond to bare aluminum very well using epoxy. You only get a small percentage of the base material strength. That's OK if the airplane was designed for it, which the KF probably was. But if the wings have been damaged or hangar rash bumped, you should look to see that none of the rib glue joints have cracked.
Check for any wear or worn holes in the wing attach fittings and strut attach fittings. It is a fairly light duty structure, so I would expect that any excess loads from turbulence or G loads or hard landings would manifest themselves in a little looseness in the bolted fittings. This is not a prediction or trying to spook you, it's just some potential safety stuff you should look at during a pre-buy.
On an airplane I owned recently, we lifted the airplane off the ground on one side by lifting at the Port wing/strut junction. As we lifted it, we heard a faint CLUNK coming from the wing root attach fitting. Sure enough, the holes in the fuselage longeron fitting, and the holes in the spar root fitting, had worn oval a little. And this was on a thick steel fitting on a certified airplane (which I agreed not to mention here).
There are also a fair number of commercial grade blind rivets on the Avid/Kitfox design. Again if it was designed for this it's no problem, but the pop rivets will get looser and move around faster than a Cherry or AN rivet. So look for any dark circles around the rivet heads that could indicate they were "working" over time.
The fabric stuff is fairly easy and cheap to fix, and easy enough to do over entirely... so unless it's falling off or ripped you should not worry much about it on an experimental airplane.
Talk to experienced Rotax flyers and find out what to look for on the motor, I can't speak from any experience there.
If you buy the Kitfox, enjoy the HELL out of it! Just remember to fly it well within the limits of the lightweight structure, and take care of the engine veryw ell.