Originally Posted by Repooc17

Both seats have "unlimited" legroom. The jump seat is not a factor unless you and the FA both have really long legs AND playing footsies with each other. Also, the the jump seat will only be occupied for a very short amount of the time under normal conditions.

You do not have to leave your J seat to allow for your seat mates in K and L to get out. And, if the FA is sitting in the jump seat, generally speaking, passengers would not be allowed get up from their seats anyway.

30J > 45J if both are available.