Put the Grip King/Lambda pedals on my zoom-zoom bike and went for a short ride. I did a route I'm familiar with and I've often ridden with the same bike and clipless pedals. Didn't notice any difference in speed or efficiency, and my sandals stuck to those pedals so well! Up hill, down hill, around corners, over gravel and dirt and asphalt.

I might not drill them for pins. I'll see how they grip in the rain, and then decide. Pins can be added if they get slippery in the rain. In the dry they feel just about as grippy as my various BMX pedals. (Sometimes the pins on the BMX pedals grip so well that I have to lift my foot off the pedal to adjust the position. I was able to just lighten my foot to adjust position on the Grip Kings.)

Stopped at a park to admire the over all aesthetic effect. The Grip Kings suit that bike very well. The have a very classic look that goes well with the classic look of that bike. I should have taken a picture...