So we use them.
You can pick your seats at no added cost and we always (when we can) choose what United calls "economy plus," which is a few inches more leg room (very important for me since I'm 6-2). Those seats are just behind first class, so you get off the plane that much sooner after landing, which is very important for our Denver connection, which can sometimes be only 45 minutes, resulting in a mad dash to the next gate.
Re. reclining seats....my pet peeve is the short person who doesn't ask the tall person behind them if the can recline their seat. Instead, they just slam their seat into your knees.