13.3" seems to be the sweet spot when it comes to portable laptops. It just seems as though that extra inch makes a big difference. I've tried 12" laptops and they seem to be just too small to be useful.
I would be typing on a 12" MBP right now, if they made one. If you regularly haul your machine around, as I do, you learn to live with the trade-offs in screen real estate. Honestly, my last two notebooks have been 12" or smaller and after a few days, I barely noticed it. But when I switched to the 15.4", it was like going from a small sports car to an SUV. Everything seems huge.
for free sure, instead of my imac no lol... its not a real necessity for me.. my usb and back up harddrive keeps my work safe.. but i guess what you are asking is would you prefer a smaller mbp.. ehh not really.. not as my main computer.. but if it were a second then yes smaller..