It bears repeating: Drones Are Hard. Above are some stats on the projects I've backed. I don't regret funding any of them, since I like encouraging these sorts of projects and I learn a lot from their updates. When a crowdfunding project I've backed actually shows up, I'm amazed (I call this being "Kickstartled") and then usually a bit disappointed that it isn't as cool or useful as I'd hoped. But I admire the work that it took into getting that far, and I'll keep backing them. This is my charity work ;-)
It's worth noting that none of these have arrived yet (with the exception of the disastrous Pockedrone, the less said about the better), so these bars will rise.
I've created a public spreadsheet here if you want to add to it. Screenshot from it below: