I used to have a 15-inch Dell laptop before I got my 13-inch MBP and at first it was hard to get used to that screen-size reduction.
That said now after having this computer for about 3 years, I can't do larger laptops. It's just so awkward for me. I've just like smaller displays I guess. the iPad Air is too big for me, the Samsung Galaxy S5 is too big for me, heck the rumored 4.7in iPhone and my 4.7in Moto X are both pushing it for me.
Every time I go into the Apple Store and I use the 15 inch Pro it feels like I'm using a massive piece of equipment. Even the 27in iMac feels too big to me!
I LOVE the 13 inch model though. I just wish I could get the power of the 15-inch Pros with Quad-Core i5s/i7s and dedicated graphics cards but with the 13 inch screen size. Hopefully one day it'll happen.
Oddly enough I have a 32" TV and sometimes I find it being almost too small, and I want to get myself 20-24" display for external use on my computer. I guess I'm just really weird :/