Mallets are downhill pedals. Not only are they very heavy (more a concern when you have to carry your bike as you run up hill or over barriers), but they're also really big and have sharp edges (which would hurt when you shoulder or if you hit yourself with a pedal). If you dismount correctly, your left pedal falls right where your spine is when you shoulder the bike -- ouch!

You don't really need a big platform for cyclocross. I would've stayed with the eggbeaters but the candies are pink (and I wanted to add some pink touches to my bike). Silly, I know.