When the KC-X is discussed, it always seems to come down to a us vs them type of discussion. What really needs to be looked at is the history of the the USAF Tankers. They are not the sexiest aircraft out there (like the fighters and bombers) but it is probably the most important aircraft in the air battle space. It is a force multiplier, that allows combat aircraft to carry more ordinance and fly longer and further. This contract really needs to properly done, because it will effect so many other mission.
Many years ago when the KC10 was ordered, it was said that it would replace the 'old' KC135. It didn't. The reason it didn't was that SAC (Strategic Air Command) had it figured out. Based on SAC's experience, they figured out that during any launch, that X number of aircraft would become mission incapable prior to completing the mission objective. And based on the fact that the tankers are the heaviest used combat aircraft, the odds are that a majority of these mission incapable aircraft would be tankers. Then the more receiving aircraft per tanker, the less likely that enough receiving aircraft will get enough fuel to complete their mission. Leading to a strong possibility of mission failure.
As for the KC-X being used for other roles, it doesn't make any sense to do that. The KC135 has an upper cargo deck, which is hardly ever used. The aircraft is too busy doing its primary mission. Refueling. And that will be the case for the KC-X. It is way too busy refueling to be used just to move trash around.
Plus one other major point. The 135 has been out there for over 50 years, day in and day out. How many 50 year old Airbuses are out there? Boeing has a track record with the Air Force for building long lived airframes. If something works, DON'T F**K with it.
And it looks like someone at Boeing HQ has dropped the ball. They already have the best large helicopter out there for moving personnel, the Chinook.