I have wide feet and have Sidi Mega Genius 5.5. I have been riding on Look Keo for the past two years. I noticed that often my wide foot felt like it was rolling off the side of the pedal when riding hard. I replaced the Keo with SPD-SL (Ultegra) on my #1 road bike. Much wider platform. When I picked up my new #2 road bike last month I put SPD-SL (105) on it.
Verdict: I like the wider platform of the SPD-SL pedals.
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The Lord is merciful and gracious, slow to anger and abounding in steadfast love. - Psalm 103:8
I am a cyclist. I am not the fastest or the fittest. But I will get to where I'm going with a smile on my face.