You never need 125fcr on a vt, the sacrifice is to big. 75fcr VT can catch all.
Ill rather have the benefit of OW/LT from dracs than that extra breakpoint in a setup vs forexample necro.

PB is the overall better wepon.
Arach = slow, without bug belt you loose an ias break.
Golem = 50% slow.
Some idiots use holy freeze merc = 50%.

The range adder is really great though, so if u can have both thats nice.
GoB is the better BA version for VT as stefbef says Those extra CB hits hard.

For a VC u can consider GoD Ba.
God PB is really great though.