I've got a 12" iBook and my boyfriend's got a 14" iBook. We both like our own ones for our own reasons - I carry mine around a lot, so I like the lightness and smallness of it, and because I'm smaller, the screen tends to be nearer my face when it's on my lap, and so I'm happy with the 12". However, he's bigger, and so when it's on his lap, it's further away from his face, and he likes the bigger screen, even though it's the same resolution. He rarely carries it around, and if he does, he's stronger than me, and so doesn't mind a heavier and bigger laptop.
If you like it, enjoy it. I wasn't sure about my boyfriend getting the 14", because it was the same resolution and all that, but he really likes it, and is happy, so I'm happy. If it suits you, I wouldn't worry.