Don't know too much about Shade, but looks like the renderer looks stunning, and it's also a modeller, though a strange one. So if you need a modeller, get Shade. If you don't need a modeller, you should ask yourself what you need to do; render photorealistic outdoors scenes, as well as indoors ones, with the new Vue6 radiosity engine, and new light options. I say Vue Infinite hasincredible rendering and scene compositing power, as well as ecosystems to make even more real looking environments. Poser import is very good in Vue, but needs a few tweaks in the material editors. 3D meshes import very nicely too. Atmospherics are very good too in Vue.

So I would say go for Vue, but if you need a modeller, Vue won't be enough ( only metaballs & boolean modelling possible)