we bought this playpen after seeing one at friends' house. Our baby was 4 months old when it arrived and we have used it with a playgym on the highest setting so far. Its fab. We know the baby cannot roll off (bed, sofa, etc) or get cold (by being on the floor). Good height for adults to interact with the baby. Also, the wheels make it easy to move between rooms nd indoors/outdoors.
It was very easy to put together, it feels very sturdy (German made, after all...) and is big enough for two babies to play in comfortably (when they have friends over).
Very happy with the purchase and I am sure it will be even more useful once the baby is a bit more mobile.