Ok, so I got off after only 6 hours. So I'll be in.

Metalline act as any material-type DR beater (Silver, Cold Iron, Adamantine, etc…), which is why they are ridiculously high in the AH. A Metalline weapon will replace pretty much anything but Holy/PG and Ghost Touch.

I rarely pug, especially with my Cleric, which is why I don't gain levels very often. Then again, having 6-7 characters I jump between plus the random ones I goof off with every so often means I'm never on with a single character that much.