I live in Texas and the heat is a killer on synthetics.
At a local Payless they USED to have a Trex deck built up by a rep for demo. They had to remove it because the boards cupped, warped, and bowed. Heat is the killer.
Vinyl does not do well also, it has yellowed to an extent and stains do present a problem.
I would never never never build a deck with 5/4 inch decking boards, they will bounce and bow and just now worth a darn. Use 2 x 6's.
Again, this is my observation and opinion based on visual inspection of other decks.
© 2016 Renovate Your World LLC