All E90s use Dakota leather...Are you 100% sure you have the premium package (power folding mirrors, auto dimming mirrors, etc)? If so then it could be that the other car had the leather cleaned with Lexol or something causing the leather to softening up a little.
A quick way to check is to see if there is the double stitching on the door where the leather is. If you don't see any visible seams and stitching then you have leatherette.
Past:08 E90 335i/02 E46 325i
Present:12 E92 335i ///M sport
Future:15 F82 ///M4