All fences will lean if they are not secured in the ground sufficiently. Colourbond won’t rot and shouldn’t fall apart due to the rotting and expansion of wet timber. Diff looks.

If the palings are fine get the posts replaced or concreted in

Colorbond is a far superior fence product than timber. However, the aesthetic of your backyard also needs to be thought of when deciding. A dark coloured Colorbond fence looks wonderful against greenery.

Timber paling fences vary depending on whether it's hardwood or treated pine and whether the in-ground posts are timber or not. Ours were concrete but from time to time individual palings warped and came loose and needed to be hammered back down. The posts were still standing when we eventually decided to replace with colorbond. A fence replaced only a few years ago shouldn't be leaning if it was done properly?

Thank you all so much for your feedback. It has helped me make my decision. I love the houzz community.