Don't have any experience of "Ultimate High", but as a current mil light fixed-wing instructor I reckon any keen PPL would benefit from a little exposure to the military side of operating light aircraft.
There can be an element of 'fear of the unknown' amongst some pilots when it comes to stall/spin/extreme attitudes, and an hour or two exploring exactly what an aircraft will do on the limit can do wonders for self-confidence, even if then going back to flying a C172 or whatever. In the mil we emphasise unusual-position recovery from all sorts of spectacular attitudes, including 60 degrees nose-down inverted, as well as incipient-spin recoveries from botched aeros manoeuvres. Once a pilot becomes comfortable with those they tend to become more self-confident with flying in general.
Emergencies are another area where solid exposure to 'worst-case' scenarios will increase your life expectancy. What to do if an engine fails above cloud, or if you develop a rapid fuel leak, or the throttle cable snaps and the engine is stuck on full power. The sort of thing that some may not have considered before.
This sort of thing is great fun as well!