Couple of thoughts. The Shimano ones are very good value to try out the idea. The mountain bike 2-bolt style, as others have said, allow you to walk in the shoes, so I've only used this type. I've had forgotten-shoes days in the office with no problem. Also when I go cycling I'm normally going to visit somewhere, so I will be walking around. I'd not bother with the half-and-half style with the flat bit on the other side - I tried a pair and they were always the wrong way up ! You can get accessory flats to clip into the cleats if you ever need to cycle in normal shoes. I now use crank brothers four sided ones, where the pedal is just a peg effectively. These are easier still to clip into. However the crank brothers pedals are very overpriced, and not as long lasting as they should be.