My Speedplays are exceptionally easy to unclip from when riding. But they do not automatically release when you crash; as in going down on a hill that was a 20% grade which was a little wet, freaking out and locking the brakes. This was in full view of many tourists near a covered bridge in Vermont.
I never have trouble getting out of my spds on my mountain bike, because as soon as see anything remotely scary looking my foot is out and down! Did I say I su** at mountain biking???