It ain't too big. Hardly.
Sometimes I feel it's a normal size laptop, and the 15'' is in fact the 13''.
The main problem is carrying it, but if you get a nice comfortable bag (I prefer the messenger bags, much more versatile than a backpack) the it shouldn't be a problem.
What I like the most is the resolution, 1920x1200 is soo handy, especially if you do some content creation.
I use mine mainly as a Logic Pro machine, but it's a everyday computer, also. In fact, it's my only computer, that's how good it is.
Peace