At all times. If you are usto Leupold quality you will giggle like a little kid when you mess with a swaro.
+1
I have the 3.5-18x Z5 with the BRX reticle and I'm pretty sure I'll always have it. It'll be the glass that I compare all others against. Nightforce, Leupold, Vortex... I haven't used another scope that compares optically.