If you can get a Premium Economy/Club/First seat for only a few extra pounds, by all means go for it - same applies if you're extra tall (or extra wide
) and need the space. But for my (holiday)money, I'd rather spend the extra on a better hotel or (several) nice meals.
I was once on a (package) holiday with a super-rich guy and his wife. The rep tried to persuade him to upgrade to club on the way back (HKG-LHR). He wasn't having any, even though (being in his 80s) he could have spent the rest of his life in F without making a dent in the interest on his interest. Clue - that's how you get to be super-rich!