So far I have been happy with the projects I have backed and received my reward for, and I've been happy with the progress shown on the other products I have kickstarted. Ultimately it is a gamble whether or not you get something back for your money. At this time I feel like I am giving someone money to try to get their dream goal fulfilled, and worst case I don't get anything in return but they have oodles of experience on what can go wrong and why, and how they could fix it the next time around or what they could do better. Sometimes believing in something/someone is better than just dismissing it outright, especially when it is just money. If you can't afford to lose it (or gamble it) then really you shouldn't be putting that money into projects on Kickstarter you should be using it to pay the bills.
Does is suck when you lose money? Absolutely, but it hasn't stopped me from actively backing more projects. Juicies was my first project I backed, if I had stopped there because of the guys failure to actually complete in time then I would have missed out on helping friends from college and I would have missed out on awesome rewards from many of the other projects I have listed below who did come through and get me my award.
That being said, the only production of physical goods I have backed were (I've also backed a couple of games/art/shows):
Not Funded yet:
Pebble: http://www.kickstarter.com/projects/597507018/pebble-e-paper...
Waiting on reward/Funded:
Mobilemount Suction Kickstand: http://www.kickstarter.com/projects/674303746/mobilemountsuc...
Twine: http://www.kickstarter.com/projects/supermechanical/twine-li...
Elevation Dock: http://www.kickstarter.com/projects/hop/elevation-dock-the-b...
Received Reward:
CEE: http://www.kickstarter.com/projects/itdaniher/cee-the-usb-an...
Prop: http://www.kickstarter.com/projects/makecollab/the-prop
Revision 1 - Drafting Themed Cards: http://www.kickstarter.com/projects/onefreehour/revision-1-d...
Pulse Sensor: http://www.kickstarter.com/projects/1342192419/pulse-sensor-...
The Present: http://www.kickstarter.com/projects/scottthrift/the-present (Although, I didn't opt for a clock, I opted for "Something" as a reward level)
Disappointed/Given up hope on ever receiving reward:
Juicies: http://www.kickstarter.com/projects/laudowicz/juicies-colorf... (My first project)