I really dont like the fact that you cannot upgrade your old units. You should give us the option to repair damaged ones with resources and to level them up automatically once you move them to a town with the appropriate factory. Or just remove the factory requirements altogether.
Wow. This change actually made me create an account on the forum to post my dislike for the update. It removes so much fun from the game and it is ripe for abuse. Please reconsider doing this since it limits my options and strategies so much.