What do you look for in a good flat pedal?

I ran the cheap standard nylon pedals for several years on my 2003 Giant Sedona, and they held up to my 300+ pounds, and were lighter than more expensive metal pedals. I finally replaced them last year when the little nubs were worn so short that my foot started slipping.

I am currently using these, which are pretty grippy. Amazon.com : XLC Alloy Comfort Pedal : Bike Pedals : Sports & Outdoors