I'm riding with A520s--SPD on one side, with a platform on the other. It allows me to clip in on days where I am focused on riding, and to wear normal shoes on the days when I am just commuting to the office. I do, though, have a very short commute (barely over a mile), so I don't really need to worry much about speed or efficiency on my commute. (In reality, I don't need a bike. I could crawl that far. But the bike makes it fun.)

I have contemplated going back to toe clips. I've never fully bought into the clipless pedal revolution. On some rides, I really like clipping in. You feel connected to the bike. (Because you are.) I really appreciate them on very long rides (centuries or more), where you know at the end of the ride that you would have difficulty just keeping your feet on the pedals without them. But there are many days that I don't want to have to drag around specialized footwear and yet I still want something more energy-efficient than platforms. For exercise, I often run and bike. I'll ride to a good trail (too filled with roots for fun riding) and run from there. I don't want to change shoes, so I just ride on the platforms. It works. But I often contemplate going back to the clips.

for a year I rode with mtb shoes. It'd take me 25 minutes to get work that way and whenever I walked around they would click constantly. Now I ride with grip kings (platforms) and I get there in about ... 25 minutes and 30 seconds. I wear my nice leather shoes the whole day :)