Hand flying strategies
Concours77, you may not have realized how different hand flying in the mach number range at altitude is from your experience in hand flying light aircraft at lower altitudes.
The very high true airspeed causes the aircraft to generate significant rates of climb/descent with extremely small pitch changes. During normal level flight cruise, typical pitch inputs would be on the order of 1/2 degree, with 1 1/2 degree pitch change being a large correction. To do this requires a high level of concentration on the attitude indicator.
At the same time, the high true airspeed reduces the aircraft's turn rate significantly and thus requires less scanning effort on the aircraft heading since that changes slowly. The piloting strategy is then to keep the wings dead level which will stabilize the heading and concentrate on the pitch indication almost exclusively. The ratio of pitch scanning versus heading scanning is probably in excess of 85-15 whereas down low, it is probably more like 50-50.