Original sentence: The original design featured a galvanised steel hopper
Edited sentence: The original design featured a galvanised steel hopper, which was so robust that many are still in use today.The plastic hopper was considered easier to clean than galvanized steel alternatives;  however, it was less robust, less suitable for mixing cement in and tended to age quickly in the sheds and garages it was typically stored in.This benefited all-terrain use as the ball did not dig into the ground like a conventional wheel and steering was much easier