I love my speedplay frogs. I had SPDs on another bike and hated them. I ride a road bike with full fenders, and I have never had an issue with grit in the cleats. My shoes are SIDI mega size, the mountain bike model. SIDI is one of the brands where the only visible difference between mountain and street shoe is the mountain shoe has a lugged sole, so the cleat is off the ground while you are walking.

I have some minor trouble with hot spots, but that is a shoe fit issue that I have with most shoes. Wide is relative, especially with Italian shoes. I am seriously considering a trip to California to that place that makes custom bike shoes. Or finding a way to attach a cleat to a hiking boot.