One bad thing??? How about B as a choice prevents procurement of a long range AEW system
The deciding factor is the E2 is far to expensive, the UK rejected the v-22 at $80m as too expensive, so a $240m E2 had no chance. There are other solutions besides helicopters. However, I've read in another forum the HM2 will be used and its completion between LM and Thales.
larger resupply and air to air refuelling a/c
Again, there are options and its not like they MUST have tankers like the for the C version.
future UCAV procurement.
As yet undesigned and its not as US was going to be supplying them, they can be specified to fly from the ski ramp
That's all without mentioning the relative merits of having a larger payload and more fuel.
Basically nothing. The is plenty of capacity to add drop tanks and probably more ordnance than will be ever required. Being much lighter the B will perform much better, you can never remove the dead weight from the C.