[Rich]

I have older composite on my deck at home. It's about 20 or so years old now.

These issues maybe brand specific or they may have improved it lately, but after 20 years it's not totally maintenance free if you want it to look like the day they installed it.

1. It collects mold over time that seems to grow inside the boards, so you have to wash it with a bleach based deck cleaner every 2 to 3 years to bring back the original color. If you don't do this it may look a bit dirty or tarnished.

2. It gets hot under bare feet, much more than any natural wood deck.

3. As others said, it often expands with age, rather than contract like wood. Unless properly installed with larger gaps between boards, and at the ends, you may have standing water on the deck, or have to retrim the ends if they press against other deck parts like post's, etc. Maybe current installers know this now and it's less of an issue now.

On the good side, no rot, and no spinters.