A few more cents worth, based strictly on what I happen to like and not like.

1. I like my feet never ever ever coming off the pedal until I want my feet off the pedal. That means clipless.
2. I like to be able to walk in bike shoes or sandals. That means SPD.
3. I do not like ever having to hunt for where to clip in. That means dedicated clipless pedals.
4. I like the idea of clipless one side and platform the other side. But in reality I only really ever ride clipless.
5. If anybody wants a set of those hybrid pedals from Shimano for the price of shipping, PM me.