Always thought they were a gimmick for new guys. Had a tricky seam on a Berber job in a Tempe condo last month. My metal roller was leaving marks. Grabbed the plastic one from my kit as a last try. Pressed it down firm and the seam melted together perfect. No shiny spots at all. Anyone else switch over to plastic for certain carpets?
A Tempe condo in this heat, that's the real test right there. I would have bet money a plastic roller would just snap under pressure on a Berber. The fact it actually fused the seam without any shine is wild. Makes me wonder what else in my kit I've been sleeping on.
Honestly that shine issue is the real killer with plastic rollers. They can fuse a seam once, but try going over a wrinkle or a high traffic area. The heat transfer is just not the same as a metal roller. Seen too many seams pop open a week later because the adhesive never fully set.