Hi Vector,
from testing aircraft in other games, the most useful parameters are (in this order):
- level top speeds over altitude
- climb rates over altitude
- roll rate over speed (both directions :-)
I've also tested specific excess power in constant G/constant speed turns (as a turn performance test.)
Climb rate at a certain altitude over speed is also useful since it gives a picture of the acceleration capability.
Dives should typically be limited by Mach number, I guess that one can be provided by a very quick test.
Regards,
Henning (HoHun)