What to look for in quality mountain bike pedals? After a few rides in mucky trails, I am finding my Norco Bush Pilot pedals are getting rough and do not spin very well. Additionally, the plastic of the pedals are getting pretty beat up.

I realize the bike is not exactly high end, but what should I look for when judging quality pedals?

My intuition so far is to look for:
1) a good all-weather seal around the bearings 
2) a platform ready for rugged use (steel?).
You want pedals that have sealed bearings and a metal spindle. I would think that a plastic platform would be less painful in the event your shin comes in contact with it but, metal would be more durable. You want the platform to be fairly open so the mud will pass through.