I've now had a chance to put this scope through it's paces during 2 days shooting in the Civilian Service Rifle competitions at the Imperial. I am now positive that I made the right choice.
I have used it from 25 yards out to 600 yards in everything from cloudy/light rain conditions right though to strong sunlight, and it has performed faultlessly throughout. I found the glass bright, and the reticle clear and sharp in all conditions and at all ranges. The turret adjustments were precise, as was return to zero.
All in all I am very pleased and won't hesitate to buy the Vortex brand again.