Yeah I'm looking at the 13". I just wanted to move to a smaller footprint. I know there is a big performance gap but for some reason that I can't rationally explain, I've wanted to try a 13" laptop.
It's not a weight thing because, like you, I'm coming from a heavy-weight PC laptop and both the 13" and 15" are very light. I'm always very surprised when people say they are worried about laptop weights. How frail are these people?
Anyway, when you said that i'm "kind of interested in gaming", that is exactly right. I'm only kind of interested, so that's why I'm not too concerned about gaming performance. I play almost no games these days. BF3 on my desktop (which is currently down) and I buy about 1 PS3 game a year. I would like to dabble every once in awhile in an RTS on my laptop, (like CIV 5 or Total War), but it isn't a priority. The only time I use my current laptop for gaming is when I substitute teach and those little turds can't see. I'll play Rise of Nations.
So anyway, gaming for me is of minimal importance, even tough I'd like to play the new Total War. The reality is that that is the ONLY new game I'd be interested in and it's not enough for me to move to the 15".
This is getting longer than I intended but I keep getting distracted here at home, so I apologize if I'm meandering. The other partial reason I'm going 13" instead of the 15" is to force me away from gaming possibilities. My next year is going to be in Italy at grad school and I can't afford the distraction of Rome Total War when I should be studying and doing work. So out of sight, out of mind, in a sense.
ANYWAY... 13" for me. For now. My only major qualm is adjusting to multitasking because on my 15" Dell I often split screen between a word document and whatever it is I am researching.