I have the Zero's and can engage them very quickly. No need to spin the pedal over. I would get the stainless if you are in a wet area as the chromoly will rust. The pedals come with an adapter for three hole shoes.

What do you mean by loose? There are some who complain that Speedplay's have some side to side play after awhile but this does not effect me. I ride the hell out of them and have gotten more than its life time of use. I replaced the shoe cleat part ($40) at 5000+ miles.

Do you need a set? That is for you to decide.