Are you flying to Tokyo or Houston?  If Tokyo, you should notice a distinct and welcome improvement to how you feel upon arrival versus other aircraft types.  The increased cabin pressure and humidity really make a difference.  And I love the large windows that are at eye level.  I would pay a $300-$400 premium to take the UA 787 between Hong Kong and Denver (via Tokyo) versus other connecting options.
Now, if I fly between London and Denver, I have to choose between superior service (BA) or superior equipment (UA or D7).  What a dilemma!