That old saw about CG: "fast, cheap or good, pick any two..." pretty much says it all here...

Poser is awesome value, it has cloth, hair, shader nodes, IBL, displacement etc for a very affordable price. Which of course means that speed has had to be let go. Even so Firefly isnt bad at all for what it does and it works quite well for most non commercial renders if you have patience and work with it a litle. Its perfect for those only doing this poser thing as a hobby since it produces nice quality and has sufficient 'tweakability' in the form of the nodes that you can get pretty much what you want. And of course once you do get to a place where you are doing commercial stuff, there is a very well defined line starting at inexpensive rendering apps all the way to full featured 3d suites that cost thous of dollars. And you can pick any one of these depending on what your clients are willing to pay/what your budgets are like. Same with hardware.

eg any of the advanced render engines out there like PRMan, mentalray, VRay etc chew through multi million poly poser scenes in minutes/seconds and they render very high quality hair, textures, reflections, IBL etc. But you are also looking at high cost and significant amounts of work in loading the poser scene into the app. Which may be viable if you are rendering a 3000 frame anim for an ad and the client wants it yesterday, but probably not if its just a funny still for uncle fred on a weekend.