The consseus is that ZF looks better but the V6 has the right 60 min subdial @12 but according to Spitfire63, he has a ZF 3878 with the correct 60min subdial @12.
Also another thing is that the ZF has the safe @6 sec mod which I don't know if the V6 does, unfortunately I've never gotten on answer on this.
I personally would go with the better looking one as you'll never use the chrono anyway.