everyone has their own interpretation
of unlimited performance ----
The hard test we use , is to pull to a vertical position --hover -then proceed vertically.
this is a lot tougher than any verticals done with some momentum.
My little Petrol Petrol at 11 lbs and a zdz 40 would accelerate out of this test - vertically- very rapidily .
Not the norm --
If a model will recover and move cleanly into another vertical maneuver -such as a snap or accurate point rolls - that is what I consider unlimited vertical performance -
To each his own.