I had a chance to examine one that a friend of mine was lucky enough to have shipped to him from his KS backing. He backed earlier than I did so I'm still in the waiting queue.
Thoughts - Overall it's neat and the packaging is nice, but it does become evident that it has some build issues.
For starters, even after using the shaping tubes that are shipped with it, you still feel the need to keep them in order to keep the lens standard parallel with the film plane. The lack of any mechanism to keep the fold out portion perpendicular to the camera body is a bad omission. A pair of curved snap guides connecting the inside of the case with the fold out board to assure this would have been a much better solution.
We had to do some manipulation to the slot with scissors before the camera would properly extract the dark slide, then a few more tries with the crank as well as opening the back to push the film forward before it got in the cycle of properly extracting film. Once done, the roller mechanism does work great to smoothly develop the film with no light spots.
The shutter in our initial tries was very fidgety. When I get mine, I'll likely go through the motions to test it more thoroughly. Of 7 tries to get an image, two came out unexposed, from apparent hiccups with the shutter.
Using the bulb setting wide open in testing, which is also sort of tricky, we could see that the lens opening wasn't very well centered with the lens. This doesn't seem to have a huge impact on image quality - after all it's a meniscus lens, but it was noticeable.
The whole weight in the foil sleeve approach to change shutter speeds doesn't seem too practical in use. The sleeve doesn't always retain its shape, so I can see the exercise getting tiring and people electing to stick with one speed.
The bellows actually seem very well made and there was no evidence of issues with them.
All told, I'm still glad I bought one even if I'm still waiting for mine, though I wouldn't pay much more than I did for one. We did get a few decent results in toying with it, and I like the close focus ability and the resulting blurring of the background that you don't see with a typical Instax and its "pan-focus" approach. As to hacking, I plan to actually put a few small size plates from J. Lane in mine to do some time exposures to see what I can get.