Wrong forum...

[Ty3]

Sorry wrong forum

[HumboldtEF]

I'd say its more of a preference thing. Those that prefer plastic usually do it for its light weight. The less rotating mass the better.
For some people the extra weight from a metal wheels is preferred. More weight down low helps keep the truck planted.

Personally I go for metal wheel because there's many more designs to choose from and I try to get lighter wheels if possible. How heavy they are varies from wheel to wheel, I have some that feel close to as light as plastic and others that are paper weights.

This thread is probably okay here but the place I'd post is in the tires and wheels section.