Having done a few quick calculations across the various routes I travel, and compared the upgrade costs from Economy pre and post Feb, it appears that EKs intentions regarding the new 'enhanced' fares, when compared to the old fares, is as follows:

Old Special Fares Pre Feb: - Low cost, reasonable tier miles and we'll give you a shot at an upgrade at check-in

New Special Fare post Feb: - Low cost, crap tier miles, no upgrade possible so you'll stay in cattle class mate.

Old Saver Fares pre Feb: - more expensive than Special, reasonable tier miles, same access to D bucket as everyone else except 'specials' with reasonable cost to upgrade

New Saver Fare post Feb: - similar cost to pre-Feb, same tier miles, no access to D bucket seats for upgrade until check-in, and we'll now charge you an insanely huge increase in miles if you're silly enough to do it.

Why? Because if you want to upgrade we want you to book flex fares instead. Why is that? Because the old Flex Fare upgrade rules are now pretty much the new Flex Plus rules, and the new Flex Fare upgrade rules are effectively what was the upper echelon of Saver rules, but at higher ticket prices of course.

To put it another way, virtually everyone has had their rewards pushed down one level (or more in the case of Saver) but will be charged the same price or more. The most dishonest redefinition of 'enhancement' I have seen in 30 years of marketing.