"Those hereditary peers are there because whichever party was in power at the time chose to rush through reform of the House of Lords before they had a properly worked out system to replace it with"

That is true but new hereditary peers are still entering the House not by means of replacing other hereditary peers but instead by being given new Life Peerages enabling them to take places in the House as a Life Peer which of course is denying other potential members their places. My only point is that we have a fair percentage of seats set aside for Hereditary Peers so then maybe Hereditary Peers should enter the House by qualifying on the grounds that they are the best people to sit on these pre-allocated seats!