Further...

I've ridden LOTS of gear:

Shoes:
Nike Kato III
Sidi Dominators
LAKE (something or other)
Sidi Genius 5
Northwave

Pedals:
Shimano 600
MKS Sylvan
Time ATAC (3 different versions)
Shimano SPD no float
Shimano Ultegra SPD with float
Shimano Ultegra SPD-SL (using float and no-float cleats)
Shimano BMX Platforms with SPD centers (for BMX racing with cleats)
LOOK (using float and no-float cleats)
Crank Brothers Eggbeaters
Speedplay Frogs
Speedplay Zero
Speedplay TRACK Zero

...and that's the stuff that I can recall.

So, I'm not just speaking from what I've gathered from reading message boards. I can give you my take on the pros and cons of all of those pedal systems.

To put this in perspective, I recently had Speedplay Zeros on my track (that's track racing) bike and Time ATACs on my cyclocross bike. After training and racing on the track bike for a long time I got on the cross bike with my MTB shoes and Time ATAC pedals and literally had a sour look on my face the entire 2 hour ride. It was simply not nice. It seemed primitive.

Don't get me wrong, the ATACs and Eggbeaters shed mud like crazy. That's what they are designed to do. But, they aren't the best for regular old road riding/commuting.