Vray vs Mental ray GI

hi everyone

I know this sounds like an old question, but I need some advice.
We have to do a game cinematic...and I want to utilize GI lighting
my two thoughts are either...
1. Vray GI, or 
2. Mental ray Final Gather GI, used to bake light/shadow maps on static 
objects, NOT to recalculate GI every frame.  Obviously.  I don't think this job

has a retirement plan.  ;)

this is the project
- 3 minutes long, at 30 FPS, rendered around 1024x768
- mostly outdoor environments, a "cutesy" town
- daytime 
- textures will be simple, again, high-quality but cartoony.  
Kinda like Shrek.

So....I know Vray is fast after it initially calculates light,
but using baked lightmaps is even faster.  I think.
Any advice?  PLEEEEZ