Which are better plastic or metal gutters?

I'm getting gutters for my house and need to know which material will ending longer in the heat of Arizona and during monsoon season.
Answers:    Metal gutters will hold up much better than the plastic. Especially contained by the Arizona heat. I have tried plastic surrounded by the NM heat and they didn't hold up well at adjectives.
Plastic looks cheap- the joints are obvious. A correct metal gutter, properly primed and finished will not sag and come apart over time. I would get seamless aluminum gutters. They concluding a long time and will not leak.