I am trying to buy a carpet for the nursery and assumed that wool was the best with wool blend as a compromise. We can't quite stretch to John Lewis so have been looking around in cheapy local carpet suppliers, all of whom recommend polypropylene as it's apparently cheaper, more durable, more cleanable, feels nicer etc etc. However, every instinct I have tells me wool or wool blend must be better without any real evidence to back up why I feel this way. Anyone have any advice?