[Ras_]

You can forget the ground observer. Stealth is the reason why it can fly high all the time to avoid visual/audio detection. Non-stealth planes like F-15E are forced into High-Low-Low-High altitude flight profile. where low level ingress and egress will e.g. drastically reduce range. F-15E going around threats both ingress and egress uses about 30% of its fuel to do so. F-22 would use around 6% in comparison. So basically stealth means that you can waste less fuel on threat avoidance.