Definatly too large for a baby. Some argue the point with cup feeding, but those first few months are pretty crucial to get a good start - and climbing around 4 feet of cage looking for fruitflies is not exactly the best to get that start off on the right foot.
My little guy is creeping up on 3 months old and definatly not ready for his larger custom built 3x3x4 castle I have waitin for em.