I used to think clipless pedals were ridiculous. Then I actually got a set of egg beaters out of the C/V Box O Crap from these forums that go around...fell in love with them. It solves multiple issues. Slipping when it's raining (though admittedly that can also be solved by more aggressive flat pedals with the little studs on them..), and the ability to pull on on the pedal. I was also wrong about this...thinking that was a load of bunk, and really people were just unweighting their legs a bit. But sure enough...when sprinting, or powering up a big hill, I absolutely pull up, to the point I have to make sure my shoes are on tight or I'll pull out of them.
They do create issue of course as well. I'm not going to wear my cycle shoes all day. Though honestly I could...if I replaced the neon green laces with black...they could pass for casual black leather shoes. I've got a set of work shoes sitting under my desk I change into.