Just a word of caution regarding extra legroom seats to all those of larger frame, either tall or wide (or both!).
On many of these seats you will find solid-sided armrests, as opposed to the raise-able type. In such a seat you can find yourself actually worse off as compared to the standard legroom seat. As you are unable to slip your legs partially underneath the armrest, you find yourself wedged into an incredibly uncomfortable position and unable to move your legs sideways at all.
I fell for this one on a Jet2 733 some time ago, paid the extra and spent three hours cursing my decision. IMO the standard seats are less painful.