The advanatge of clipless over toe clips is really for hard athletic riding. If you poush hard, they will be more efficient.
Ive done lots of off-road riding in toe clips and have never had a problem. Ive been able to get my feet out of the (loose) straps during a slide down a wet grassy bank, and on ice. Even during a surprise wipe-out, my feet can get to the ground and control the situation. This is not the same thing as your feet coming unclipped during an uncontrolled crash.