I went clipless last year and haven't looked back. I've had one zero mph fall. I was turning around on a bike path and someone came up behind me. I couldn't get unclipped and fell over. I only had 30 miles on my new bike too, didn't do any damage other than to my ego and my beautiful brake handles, but oh well.

I concur that if you are just going to go out to the store and run around and stop often, flat pedals are better. For most of my riding for fitness and maybe 1 stop for coffee/beer, the clipless is better IMO. I find that I climbing is easier. I'm sure it's all in my head though. I do like being able to pull up on my pedals when my legs are burning. If I concentrate on my pedal stroke, I go faster and my legs don't get as tired.

I ride platform on my MTB though. I'd rather be able to bail out on the trails than be clipped in.