I'm in the middle of a two-year study of clipless pedals on my road bike. The results are still inconclusive. I can't feel any extra power. My feet are always correctly positioned. They're plenty comfortable. I've fallen twice due to lack of time/ability/quick-wittedness to get my feet out (Club Tombay.) As a result, I'm not seriously thinking of replacing the platform pedals on my touring bike.

I've never liked clips and straps - I had a few falls when I was younger, including one that could have cost my life - slipping on gravel, having my foot stuck, and going down in front of oncoming traffic.

My platform pedals give me two good advantages - I only bring one pair of shoes on tour - not a riding pair and a walking pair - and that saves weight, especially with my size 14 feet. The other is that the shoes I bring are extremely comfortable and excellent for long hikes - I buy a really good pair of running shoes before each tour - a nice way to pamper one's self. I can see the advantage of 520's - SPD shoes are okay for walking - but okay isn't the same as excellent. Admittedly, I've never tried walking far in them so I may be wrong. Indeed, my opinions seem to be in the decided minority, so I may be wrong about everything. However, my choices work for me and I'm satisfied.