I've supported 5 successful projects on Kickstarter (DemonWars tabletop RPG, Pier Solar HD, Yooka Laylee, Bloodstained, and Bard's Tale 4). So far the table top game (a really awesome high quality rule book and campaign guide from author RA Salvatore) and Pier Solar have been delivered. Nothing has really happened so far to make me want Kickstarter games less. The other three games on my list are all scheduled to be released in 2016 and 2017. But I'm realistic. I know they will be pushed back, just like a good portion of publisher-backed games. This is commonplace in the industry and it should always be expected.
There were some hiccups in the Pier Solar project. Mainly that the game was released digitally about a year before we got our physical copies. Not sure what the holdup was. Maybe they ran out of money and had to fund the physical releases with the sales of the digital copy. I don't know. And some backers are claiming they still haven't gotten theirs. But the fact is that I got my game (physical DRM-free PC version) and it's great. Even the base physical copy is put together well. So I can't really complain.
Regarding the other three games I have backed, I trust IGA, the former RARE guys, and The Wasteland 2 guys to get me my game and any physical rewards I deserve. If I get burned, maybe I'll change my tune. But so far so good.