Got to drive a car again, and wanted to add clarification on bottoming out subject.
Yes they will bottom out on big bumps (mind you much less than TEIN adjustables from coilover kit), but in my opinion it is not due to stiffness, it is due to reduced stroke. While the idea of dual 50lbs/175lbs rate is sound, problem is that the middle "locked" part is too big, and effectively in addition to 1.5" lowering it is also taking another 2-3" out of stroke. Which is in a part compensated by stiffer spring.
Unfortunately on many occasions the stroke is defined by size of the bump as at higher speed car will not get a chance to jerk up, not by the spring rate. This would not be an issue if you rarely load car and don't live in area with big potholes/bumps.
The Eibach and similar designed springs with more modest difference in rate (say 160/100lbs) would inherently have more available stroke, and would work better in such conditions.
From measurements it looks like the effective stroke of AD springs is ~4", and on OEMs it is 7", big difference.
View my fuel log 2015 Mirage DE 1.2 manual: 46.4 mpg (US) ... 19.7 km/L ... 5.1 L/100 km ... 55.7 mpg (Imp)