Along with the technical issues, some serious thought should be given to the strategy that is behind the "Need" for this aircraft.
Yes...going far quickly then being able to. land much as a helicopter does is fine if the rest of the forces can fulfill their roles.
The 280 is a Squad mover comparable to the Blackhawk it is to replace.
Moving Squads is nice....but how do you move Battalions along with the supporting arms that include artillery, mortars, vehicles, and supplies (food, water, ammo), and medical support?
Chinooks move more and will be in the mix....does the Army incorporate Air to Air Refueling for the Chinooks?
How about the Apache gunship support....it cannot keep up and does not have the legs to escort the 280.
If we are talking combat operations it is a combined arms operation and not an admin type transportation of troops.
We should look to how the Marines changed their operating methods when they fielded the Osprey to see how that combined arms thing works at the far end of the flight for the 280 if it is envisioned to be an "Air Assault" type attack.
We saw the 101st Airborne deploy a FARP to support the Apache attack deep behind Iraqi Lines (the one that ended disastrously for the Apaches).
That FARP required Chinooks, Blackhawks, and a lot of troops and equipment for defense of the FARP.
How does one do that in Pacific?
The Marines have settled upon a "Go Light" strategy and although with slightly different mission sets there are similarities between the anticipated Army mission and the Marines now that the Army is looking to Tiltrotor aircraft.
Then there is also Congressional Politics that shall. play a role in all of these planned acquisitions.
As said by one long serving member of Congress....."It is not about the Dollars....it is about the Zip Codes of where that money is spent.".