Thats a good idea, number between 1-10 performance, sizing, durability, geo, quality etc.. If it gets 3/10 or lower you are able to comment or something like that. Problem is verification, which can be resolved with a token system. Lets say after 10 or 20 post and 1 month old members can vote. If admins are willing for something like that, why not? I believe result may be more accurate than opinions.