Where would you use the guaranteed upgrade (I wonder if this is only valid if there are seats available or whether they would downgrade paying C passengers) on OK? Longhaul is almost non-existing and it is a lot more comfortable to sit in an exit row than in C on shorthaul. The only people who could benefit from this are those flying between Prague and New York (and only if the upgrade is really guaranteed regardless of the number of paying C pax) a lot.