I think 2.25 seconds would be a good spread to bet over/under on.
3000
Gebremeskel 7:34 (indoor) vs Rupp 7:42 (indoor)
(I will give Rupp a 7:35.x for his 8:09.8 two-mile)
Edge: Gebremeskel
5000
DG 12:46 vs Rupp 12:58
Big edge: Gebremeskel
Racing chops
Gebremeskel: Beat Farah IN THIS RACE AT THIS MEET...WITH ONE SHOE.
Rupp: Has NEVER touched Farah, given numerous opportunities
Massive edge: Gebremeskel
Head-to-head
Gebremeskel 2nd in 2012 Olympic 5000 (13:41), Rupp 7th (13:45)
Same pattern in Daegu: 3rd vs 9th, four-second gap.
Undebatable edge: Gebremeskel
I am going to say Gebremeskel runs away with it, 7:32-low to 7:34-high.