You didn't pull that HUD down onto your gunsight so it's in your line of view at all times? One of my squad mates put his above the gunsight glass, mine is below on the barrel of the gunsight mechanism. From experience I have a good idea of my rate of climb by my speed, either in normal climb out or in zoom climb. If Hitech is willing to add rate of climb to that HUD, it would be a good thing.