3rd How much room do you need? The 25 holds A LOT! I can fit 2 makeup cases, a pair of 3" wedges, a bottle or water, wallet, camera, kleenex packet, keys, cell phone and a light sweater. By this point the bag is really heavy and hurts my forearm after awhile. If you always carry that amount or more, you may want to consider a 30 but keep in mind it might get heavy. But the pro of a 30 is that you can use it for school, you can fit notebooks and such inside. It can also be used as a small overnight bag which wouldve come in real handy for me a few years ago (I REALLY wish I got the seedy sooner).