My ds is now 6 months and he is a big baby (20 ibs, 9-12month clothes). He's currently still in his sleepyhead and I'm not sure when to try him without it. He's sleeping ok, although he's going through a period of waking at 4am some nights. Can anyone tell me when they chose to ditch the sleepyhead? Do you think the if it ain't broke theory is best?