I have gotten 100% of the things that I invested in too, but never felt bad when the schedules got pushed back, or it looked like the thing might never come.
It is fun if you are chill, but if you really really expect something, even the wait for a project that produces fruit might be too much.
For example, I invested in a few HexBright flashlights. They eventually came, and were cool... it took a really long time. Watching the team design them, and watching progress update videos was fun. During the wait, I had to buy a different flashlight to satisfy my flashlight needs, from a real store. Kickstarter is not a store.