I'm going to use some of my vouchers and/or points to get an upgrade HEL>JFK, buying a Y ticket. I'm really far ahead in time, going there mid October, so I guess availability should be good, and I'm AY Plat also. Question though: they have all this different booking classes; Economy Special, Economy Saver, Economy, Economy Flex and Economy Fully Flex - can I upgrade all these classes? Or are the cheapest ones, Economy Saver and Economy Special not upgradable at all? If someone have any experience of this, I'd be very glad to have some info. Thanks.