Pack n Play binets?

We were never comfortable with the binet portion of our pack 'n' play. It seemed to sink when we laid him in it but maybe it just wasn't put together well (someone else put it together for us). I'm planning to try using it again with the next baby but if I'm not comfortable I'll probably just use the bottom portion. But we loved the changing table part and the bottom portion, we just weren't comfortable with the binet part.