I've preordered 1-camera and a few of there initially offered accessories.
There was quite a long period, that ended about 4-6 weeks ago, of very little updates (either via e-mail or social media). But, now they are doing live video casts, there responses to questions in the Earlier Backer FB Group are decently quick, they are posting little videos from use cases, as well of still doing the standard monthly e-mail updates. They seemed to really get on it directly after announcing that there was going to be a 2 or 3 week delay (they were specific, I can't remember exactly) due to a supplier not being able to supply a part. Their live video casts have been really interesting regarding some accessories they will have have to offer. I'm guessing those will be available when they release their updated full and mobile website (that they also previewed in one of those video casts).
I've backed 5-different projects through Kickstarter & Indiegogo, all having to do with tech gadgets. All have delivered their product, and all were delayed to some degree. Of my experience with these 5 past instances, Revl will be in the middle as far as delay, but by far the most polished product & ecosystem supporting the product. The trick is can they sustain and really grab some GoPro market share. I think they they can, and REALLY REALLY hope they can. And not just because of the money I've put up for the Arc Camera right now. That has very little to do with it. From their, now more intense, product/accessories/tech advertising push you can see that Revl appears to have a good sense of the camera/video tech as well as anybody, but a much better sense of the use & users coupled with mobile/social culture. That's just my take from seeing the snippets of what they show they are working on in their shop. But it looks like mobile editing, via the user editing in app and AI help, video & physics info, and sharing are all going to be much more enjoyable. As someone who plans to use this little guy as important part of my travel kit this last bit is particularly important to me, and was not expected to be part of the overall package when I initially ponied up the money.
All the above said, we'll see how it shakes out. :-/ I'm hopeful, but will reserve judgement.