I just read this entire thread, I greatly appreciate the non-biased opinions and responses.
One thing I think most agree on is those "Clips" or cages on the pedals are not real good.

The clipless units seem to be a little more efficient, with some learning, can keep the foot on the pedal in those heated moments.
On the down side, folks like me who ride with anything from steel toed work boot to sandals kinda rules them out on my cargo bike. Not to mention the added cost$$$$$.
On the dirt I got my own ideas.
But when I get my road bike I want for a year now, I just may put clipless pedals on it and MTB shoes.

I do have a concern, I have tried clipless, pros/cons bla bla bla, but whats this talk about knee pain?
I ride because the doc told me to for my knees, will clipless pedals affect that?