We have a 5mth old and have just started using it....i just bought the tray too - which i didnt have for my other two children. The tray defn makes it more useful - we will use it as a highchair too until he's a little bigger to go into a high chair.

Its on my list of top 3 items to buy when having a baby.......

Ive heard its not for all babies though....some like it, some dont....