I came from riding all my bikes with PowerGrips for a year to going with CrankBros on the commuter and Speedplays on the weekend bike. So, I consider myself lucky because the PowerGrips has conditioned me to twist my foot out to get out of the straps which is basically the same as clipless pedals.

So far I have not fallen down from the CrankBros' but I have fallen once from the Speedplays. I was trying to make a u-turn on a slightly uphill, narrow road while going very slow. Needless to say I lost all momentum while in the middle of the u-turn and crashed on my left side. I sprained my left wrist and scraped my knee. Before falling down I remember thinking to myself "This is not good. Unclip, unclip." -Sigh-