Nice title. I know which I'd have (although Airbus have missed a trick in the design).

What did they miss?
A lot has been made of the limitations of the KC-330 due to the strength of runway/taxyway/hardstanding it needs (compared to the KC767), due to being a very large, heavy aircraft but with normal twin bogey undercarriage. The A340 airframe, which is virtually identical, has a third bogey mounted centrally under the fuselage, which if it'd been incorporated on the A330 tanker, would have lessened this limitation. Seems silly not to do such a mod, when the basic engineering is already there, and which ultimately could lose orders.
In fact, someone who was associated with the unsuccessful Boeing based bid for the UK contract, told me he thought that other than the above, the A330 was the superior tanker. It's just such a minor thing, which to those not wanting to spend gazillions on infrastructure, could be a major limitation.
Thought of the center tires last year but banished the thought, reason:
The tires on the A330 frame are way wider then the ones used on the B767, which allows you to distribute the weight evenly. Much like how the C-17 has wider taller tires then the C-5 since it has less wheels, and has a pretty wide foot print as a result. And gear & wing tech has come along way since the introduction of the DC-10 and L-1011, aren't the only 2 planes that have center gears now a days are the A340, and A350? B777F, B767F, B757F, A310F A320F, & A330F, do not use the center gear, and they have not had any issues.
And besides as what was mention, almost all the USAF bases have had there runways redone, B-52's B-1's, and B-2's carry alot of weight on there tiny gear, but manage fine.
Also on a side note about space, wing clearance, and fuel load, we did a basic figure based on one of Boeing's complaints. They brought up that you would not be able to get as many 330's on the ramp as 767's. But if you had 6 767's on the ramp with a max fuel load of 204,000 lbs a plane, you would have 1,224,000lbs of usable fuel to spread to other heavy's and fighters for the Area Of Operation(AOR), good for people needing fuel, but now they have to be a base that has the min 7,000ft+ runway.
But on the other hand you would only be able to have 4 A330's on the ramp able to have a max load of 245,000lbs a plane, but with a total of 980,000lbs of usable fuel. But wit the same take off fuel load as the 767, it can take off on shorter 5,000ft runways allowing it to operate much closer to the AOR using the same runways that C-17's use daily.
And just by sending up 2 planes with 200k fuel loads, a third A330 can take off and Air Refuel the first 2, be maxed out and stay in the air longer over the battle field. So in the even that some fighters are running late due to providing close air support, or recon duty, and have to stay in the fight longer, the A330 is already closer allowing the fighter to have an extra few min of providing suppression fire, before it has to hit the tanker. And since the tanker is closer off the start, it means the fighter can get back quickly and keep providing much needed suppression fire for ground troops. 
But on the other hand if they did decide to use the same base for the A330 that the 767 was going to use and you are able to get 6 of them there and not 4, it gives you a total of 1,470,000lbs of fuel vs 1,224,000lbs of fuel by 6 767's. And the extra 246,000 of fuel that is available means:
-A C-5 can now go direct from the AOR to the states if the mission needed it to with out stopping in Europe for gas.
-A C-17 taking off at max load now can go further with it tanks topped off, maybe making it to Main or Dover if the winds are in its favor.
-An E-3 or E-8 can now stay in the air longer tracking targets
-The RC-135 & EC-135 can stay in the area longer gather information.