Foot retention isn't necessary, but some of us prefer it whenever it's available. It becomes a habit, and it's pretty harmless as habits go.

I happen to like these pedals and their ilk. They're SPD on one side only. On the other side, you can use street shoes. They are weighted in such a way that you can choose the side you want by flipping it forward or back. I get in quickly almost every time with no fumbling.



Nowadays, when I buy shoes, even shoes that will not be primarily for cycling, I try to buy SPD shoes. I have about four pairs of SPD shoes of various types. One is a racing shoe, one a hiking shoe, one a running shoe, and another is a sandal. Actually, I have two of each of the above, since I have two feet.