Mental Ray (3dsmax)

Mental Ray use Global Illumination; a photon based approach.
GI is really good at producing details and advanced effects, but renderings are grainy if no interpolation is used.
Render time is 45-50 minutes per image.

Pros:
Easy texturemapping (native 3dsmax).
Support for 3dsmax architectural materials.
Good for detailed exterior models (interiors are time consuming).

Cons:
Complexity (primarily concerning Mental Ray materials).
Poor representation of MR-lights (in 3dsmax).
Interpolation of glossy reflections are extremely time-consuming.