From the experience of trying things both ways, I agree with those people who say that using a starter is the way to go. It's so easy - I mean, you make wort and ferment your beer, right? Well, your starter is a mini-brew, but it's immesurably easier, quicker, and so much easier. Just let the yeast activate like crazy for about two days and get to high krausen and dump them in to your wort on brew day. Combine that with a couple minutes of pure oxygen and you'll see bubbles in the airlock before you believe it's possible! "They" say that doing this increases your attenuation considerably, and I believe that's true, but I don't have any real experience that helps to suggest or disprove this.