I currently have spd's on both my commuter bike (mtn bike) and road bike. I have shimano mtn bike shoes that I wear. I have no problems on my commuter bike, but after 40 miles on my road bike, it feels like I have a hole burning in the bottom of my left foot under the cleat. I was determined this year to look for a replacement pedal/shoes combo for my road bike. I though sidi's were the way to go for shoes, but am perplexed as to what type of pedals to get. I only had the foot problems when I rode until I got a new pair of winter walking shoes and on my first day of wearing them, I had the same problems with my left foot where I thought a hole was burning in the underside. Now I am not so sure it is the pedal/clip/shoe combination, but a problem with my foot .