Why should my feet be attached to the pedals?

[TsPoet]

Does anyone use Powergrips? I am thinking about trying them to ride more efficiently while still being able to wear whatever shoes but would like to hear from people who have experience using them. Are they easy to get your foot out of at stoplights etc.?

I love the powergrips on my trike. I know lots of folks who like them on 2-wheeled bents. Maybe I would master them on a two-wheeler if I needed to, but I find them harder to get out of then my clipless pedals. It's a similar motion though, twist out.
They work pretty well to improve power transfer and keep your feet on the pedals. Not quite as good as clipless, but you can get a fairly tight connection and twist out with them. I do really like using street shoes on my trike.
You could also get pedals with two sides - clips on one and platform on the other.