If the flight is half empty (which doesn't happen that often) and the back of the plane is deserted I may move to a row where I can have it all to myself, pop up the armrests, stretch out my legs, etc if I'm on my way to my final destination.

If I'm making a connection I prefer to get off quicker, the extra 10 or 15 minutes get off the back of the plane can make a huge difference.