Define "toy"? My macbook air can do everything my dads macbook pro 2010, intact it seems even faster than the pro. The air is FAR from being a "toy"
Anyway the macbook air is FAR more portable in terms of weight, especially my 11", HOWEVER unless your actually going to use the portable i.e. carry it around a lot, then it makes no difference.
I'm a student and needed a portable yet powerful computer, the more portable the better and the 11" makes the 13" seem like a brick. If your just going to keep the mac at home 90% of the time, then get the mbp.