Unreliable Airspeed
Im new and under training. In my company, at 100kts PNF will call out "100KTS" for a speed check with the PF. Therefore, in this situation on the T/O roll with one of us having an unreliable airspeed or if both PFD speeds are not sync, below V1, we would stop. In my humble opinion, i totally agree with this policy of my company because i don't see any good reason to get off the ground with such an abnormal situation prior to V1, let alone, V1 has been calculated to provide you with sufficient distance to abort the T/O. Also, like Slasher said, it ain't so easy no more in a dark night with poor weather conditions if you decided to continue. But, thats just my opinion.