I am not worried about "winning" as the Imperial. I view the game more as an "RPG Lite" rather than a competitive-cooperative game. This is good, as my gaming group does not have the time for a proper RPG, but stil wants a little more than board/miniatures game.
As such, my view of the "Imperial Player" is very much the Game Master. I enjoy this role - re-living my youth as a DM. In fact, I often have some minor RPG prior to the mission, giving "tid-bits" based on player interaction and out of mission attribute tests. An example is an interaction of players in a local bar prior to the "Vipers Den" mission I am not worried about "winning" as the Imperial. I view the game more as an "RPG Lite" rather than a competitive-cooperative game. As such, my view of the "Imperial Player" is very much the Game Master. I enjoy this role - re-living my youth as a DM. In fact, I often have some minor RPG prior to the mission, giving "tid-bits" based on player interaction and out of mission attribute tests. An example is an interaction of players in a local bar prior to the "Vipers Den" mission. Based on attribute tests (with or without modifications pending character action), the players may be informed a bit about the mission, or what to find. Not enough to spoil the mission, but enough to give some "edge" - just like a rebel covert group would do through Intel, surveillance and contacts.
Has the Imperium won in my campaigns? Yes, but that is not what I am worried about. For me, it is the Game Master role that is the fun. Heavens forbid the players ever read the Campaign Rule Book!