re GI and SubD's
I'm wondering if MR for Maya has the same function that xsi has for sub's and mental ray (its default renderer).
If this is so,
There may be a node (haven't checked as yet) called 'Geometry approximation'.
This node tells MR to calulate geometry's subdivision level. ie. nurbs and poly's. This is a rendertime function. Which smooths the geometry ala subd.
After saying all this I should check that it indeed implemented in MR for Maya.
Otherwise just use Maya's native smooth or CPS on your poly models along with MR.
Hope this helps.
Mayan elder......only in years.....