Just out of Curiousity... Carbon

well an £800 carbon frame will be a decent frame, in the main. so will an £800 steel one.

you can get more, and less expensive versions of both.

frame material always used to be a horses-for-courses choice, I don't see why that shouldn't still be the case.

each has different properties, which influence your choice, there is no "better" just what's better for the application you want to use it for.

I better rewrite it; I think a £400 steel frame would performance as good as an £800 frame, given the cost of material and the process of making frame, surely a steel frame is not hard to make compared to making carbon?