I was wondering if someone could help me with some perspective here. I've been riding Speedplay Frogs for a few years, prior to that I was mainly in the Mountain Bike community riding M540-SPDs.
I went with the Frogs for the longer distances of the Randonneuring events, since I imagined that they had a better or "bigger" platform than the SPDs. My thinking was that even the Shimano Touring pedals (the A-520 style) only provided the same platform as the standard dual entry MTB style. I'm not interested in Road pedals, since I want a recessed cleat.
I wanted a bigger platform to avoid hotspots, although I also believe hotspots are largely dealt with via good soles and I run Specialized's carbon Expert MTB shoes. My experience with the Frogs has been fairly good, I love the easy float. The main issue I have with them is that from time to time, if I am tired or distracted, I don’t disengage properly {I'll explain this below for those interested} and there is no forgiveness in the Frogs for such foolishness, so one stays very connected to the bike as one falls over onto the road at a stop light. I have ways around this, of course, disengaging early and all that. When I used the SPD MTB pedals, that forgiveness was enabled by a change in tension.
So here is my question, just thinking of the longer rides experienced in a Brevet series, does anyone have a sense that the Frogs vs SPDs make a difference at all when it comes to long distance foot comfort?
Explanation/Review about Speedplay Frogs and Disengaging:
Having used clipless pedals for a long time I am fairly confident in saying that the Frogs disengage really well, most of the time. But I have found that if you happen not to have an exactly lateral movement when twisting off the pedal, the cleat sometimes sticks on the pedal and this induces a little panic as you're balancing there and the intuitive response is to use more force, but that only makes it stick more. I should point out that this mainly happens when I am suddenly in need of disengaging, not when I have time to spare (which can actually be a problem, since that's when you really do need to disengage fast).
By "exactly lateral" I mean that if there is any noticeable upward or downward angle in your disengaging, it won't disengage. So yes, I have gone over in traffic at a stop light because of this. I run Speedplay Zeros on another bike and have never gone over or had this problem, and I run SPDs on my MTB and again never had the problem. I emphasize that I have never fallen with clipless pedals before, only after using the Frogs. I deal with this by simply trying to avoid having to disengage in a hurry, but the nature of this means that it's an unpredictable scenario.