Currently, I use my 13" MacBook Pro as a second screen next to my 24" (1920x1200) monitor, but, I’ve been kicking around the idea of dropping down to just the laptop.
I’m just getting tired of constantly unplugging everything from my laptop whenever I want to carry it off. Last year I actually did this very thing and it lasted quite a while, maybe a few months.
Way back in 2009, when I bought this laptop, I debated heavily whether I should get the 13" or 15" model. My previous MacBook Pro was a 15" model and I absolutely loved it, but I was wanting something more portable. These days I’ve been kicking myself that I didn’t go with the larger screen. If I had that laptop I probably wouldn’t have even picked up the external monitor.
Going from 24" + 13" worth of screen real estate down to just the 13" will be a challenge, but, I’ll just lean on full screen apps and spaces more.