Today I'm flying halfway across the country, and my girlfriend drove me to the airport. She did me a favor by checking me in online and printing out my boarding pass, and thought she did an even better job by getting me out of the normal aisle seat that I had and putting me into the exit row.
Now, if you're not a very large person, you probably don't notice the little things on airplanes. You hear that exit rows have more legroom, and that's generally true. The important thing that goes unnoticed, and why my girlfriend didn't realize the disservice she actually did for me, is that the first set of exit row seats do not recline. If you're 5'6" and like to kick your legs out like a retard, then this won't make much difference. The seats on airplanes don't recline much anyhow. If you're 6'6," and can barely fit your legs into a normal seat anyhow, chances are that you have a taller than average back.
Why is this important? They design the seats to give a sort of neck support to normal-sized people. This ends up making the very top part of the seat stick out farther than the middle of it. It also disallows a taller person from sitting up straight. They're pushed forward. Imagine sitting with your back straight, but lean forward about 4 inches. Now try to do that for 4 hours. It destroys your back and neck. The solution is to recline the seat, and that way you can enjoy 90% of the comfort that a normal-sized passenger has if they leave their seat up.
Anyhow, if you're checking in tall friends of yours, do not do them a favor by moving their seat to the first exit row. They're by far the worst seats on any plane.