That's what I thought, material tweaks are needed. Standard Maya materials aren't suited for glass right out the box because the reflectivity is pretty constant regardless of the viewing angle, extra nodes are needed to simulate Fresnel reflections (like sampler info node), or you could use the mia_material_x, it behaves more realistically and even has a Fresnel reflections checkbox. Is there any reflection blurring on the phong/blinns? If not, then I can see why the reflections look crisp and strange.