The 215/40s will have a
slightly taller side wall than the factory 205/40s, so they should be a little more 'cushy'.
But the other factor which we do not know is how does the side wall
construction, and therefore rigidity compare between the two different brands?
Also, you are doing the opposite of stretching these by putting them on a 7" wide wheel, so that may contribute to them riding softer as well.(
)