Would love to have a HUD. The main reason for omitting it is the lack of space - both overhead and on the coaming. This thing is tiny! Secondly we've got such a small allocation for weight, that we can't afford to have 'luxuries' like HUD in the standard fit.
Would a blended display of synthetic vision and IR camera not be good enough to fly even though it's head down?
For the military and SAR versions, helmet mounted optics would be the answer, but we can't really envisage bizjet pilots wanting to wear them for day to day operations.
All the screens are identical, so for dispatch it would be a quick job to swap them, and the avionics behind them will reconfigure should a channel fail.
From my research, display screens now have an MTBF of around 16,000 hours, so I'm fairly confident that screen failure would be a very rare occurance.