[goldcd]

It's good stuff - but not cheap.

For decking where you're going to have to clean it yearly anyway, I wouldn't bother (no real effort to just add on some maintenance) - and probably works out cheaper even with a few replacements over decades.

Where it shines is where it's a pain to replace and a nice bit of weathering is what you're after (say the eaves on a roof) - not too expensive to run a plank around the perimeter and no ladders/scaffolding/treatment required for the rest of your life.