Might just be me but the V1 call is only part of the go-nogo for me. What defines the go-nogo is the actual indicated speed. If the PM chooses to call V1 early I will assume the ASIs are reading differently for some reason and be prepared for unreliable airspeed. If I am handling I will have the ASI in my scan and know when I am through 80kts, am passing V1, and rotate. If you are dependent on the V1 call or rotate call you will have lost an opportunity to find out that your pitot is blocked..