Decking replacement - what would you recommend?

[EagleRay]

My small back garden has a fairly large expanse of decking stretching out from the patio doors and was laid around 9 years ago. Of course it was lovely when first laid but over the years it's become slimy and is really horrible to walk on after rain as it gets waterlogged. It's a marvellous home for woodlice though as the current population of 10,302 little bastards will testify

Every so often I try to clean it with a pressure washer but it takes forever, and I don't do it often enough.

Anyway, garden has now been redesigned, which includes cutting back the decking area to an area just over 2 x 3m and I need to choose a new surface. Was thinking about going for something deck-like but not conventional wood. As it's a smaller area, I can hopefully afford to spend a bit more per square metre too.

I keep reading about composites, heat treated wood, etc but not sure which would be best. Has anyone had any of these materials laid?