Galen has more experience in sit and kicks and has shown he can close well (ie Chicago last year) and has experience on the course. He takes it in a slow race.
Farah has experience in fast paced races and can go out in 61 and at least still somewhat survive. Take it out in an even 63 and Farah might be able to chop in down and outrun Galen. Yes, Galen went out in 63 flat at Prague and managed it well, but that's probably a pace that suits both of them equally well, only in this case, I think Farah can close faster if the first half is respectable. It won't go out any faster than 64:00 though.
Overall I think there's a higher chance Galen wins in a slow race than Farah winning in a fast race, and with Galen's experience I'll give the nod to him.