The Dexcom G4 sensors are reported to be more accurate than Dex7.
You're right - you are lucky, and I don't think you can make a 'bad' choice. Both will be great.
The primary plus for the Vibe is the color screen and being waterproof.
I'd say the advantage for MM Veo is that it's been available longer, so some may feel that makes it more reliable.
G4 is approved for 7 days, Elite for 6 days (I think). But actual usage of both can usually be extended. My guess is G4 would last longer, but you may want to get input from Enlite users. Dex7 sensors often last 10-21 days. This may impact your actual OOP cost.
See if you can arrange for a trial, or at least a hands-on demo of each.