FWIW, I'm 6'3". Funny thing is, I never have a problem with legroom; they're long enough they fit under the seat (my feet reach to the metal bar blocking the underseat) but unless the guy in front has his seatback in full-recline mode, my knees are usually good. I guess more of my height is "torso" than "leg".

I won't pay more for exit rows for this reason, since IME many of 'em don't recline nor have tray tables attached to the seatback in front (the folding ones are never as stable) and aren't as great to me as they are to many here- in fact, the reason I'll pay for F, seatwise, is 'cause of the width (I have wide shoulders) vs. the legroom.