I have a zip and link at the moment size is 6ft by 7ft. I am tall and weigh 14 stones. I would like to be able to breath easier as I get very hot through the night. I have a hand made tufted mattress at the moment but would like a slightly smaller bed but as I am tall would still like a long bed. Medium might be too soft but I don't like a hard bed I have a bad back so not hard and certainly not soft.