There are so many configurations of planes, which can vary by only a few rows, but could mean the difference between having a ton of leg room or not being able to recline. Just put in your expected flight details and you can easily see what seats are best. (A side tip: If there are two exit rows over the wings, try to avoid the first row as they won't recline due to another exit row being behind those.) You can also see the type of plane scheduled to be flown, which could mean the different between a year-old movie on a loop or a gallery of movies and music at your disposal.