I want to know how plush is the mattress. DS hasn't slept in a pac and play since he was 4 months old. I don't think he would find a pac and play comfortable (maybe I'm projecting myself on him again). The BabyBjorn looks like a nice alternative for his travel bed if the mattress is more plush than the cardboard like mattress in a typical pac and play. Does anyone else have alternatives to travel cribs for an active child?