Depends how little your little one and what rides you're looking at doing, but some general thoughts...
-Flight of the Sky Lion has a horrible queue (especially if it's warm), and it does move quite slow
-Ninjago and Dragon queue times often are inflated / over stated
-Log flume gets you wetter than you'd expect
-There's lots of play areas about; most of them are pretty decent!
-Food is expensive (even by Merlin standards)
-The duelling coasters have a quick moving queue, even when the queue is full