I don't have Vue yet, but I seriously think about buying it... but I think I can answer some of your questions. Vue 5 has not mover 5 included, but it can import still poser files even without it. HDRI is a way of illuminating a scene. It uses a pic with more than the color info to simulate the light coming from a real environement. Only expensive software uses hdri today, Vue5 must be amongst the cheapest. The rendering engine in Vue 5 not only allows the use of HDRI, but uses Global illumination and radiosity. Vue 4 doesn't.