Della Santa, Bike Friday Air Glide, 1974 Schwinn Paramount, Cannondale t2000 Touring, Cannondale r500 Road Silk, LeMond Buenos Aires, Trek 7000 mtn bike, Sears and Roebuck[ made by Puch. I have had up to 36 bikes at one time. I am a sick person.
I have used Shimano SPD pedals and cleats for years and have never fallen because of them. When I first started with them, I took a friends advice to set the tension to the lightest tension setting, for easy in and out.
Never had a problem with them.
The one and only time I went down using clipless pedals a drunk guy pulled me down. Dunno if I would have caught myself with plain pedals or not, but I do remember not being able to free my foot quite fast enough.
Practice unclipping quickly if you are worried about it. They say you have to do a new action a minimum of 50x (not all at once) before it becomes ingrained.