I ride Speedplay Zero's.
--Springs fall out? There aren't any springs I know of. I have about 3k on mine. "Zero" problems.
--No trouble with dirt. That's probably be in the cleat, but a quick look at it before every ride, which you should do anyway, can take care of that.
--I've never ever clipped out unexpectedly.
--The pedal is small, but the Cleat is huge for a big wide platform.
They are great for two sided entry.
But check the tension on yours first.
I probably have it wrong. It was screws that come loose not springs. However, a little locktite would solve that problem.
As for the adjustment I don't see any on the shoes. Just for and aft movement.