Where to start
To summarise
Once the render button on PW is pressed it is quicker at producing a noise free image. However this image is never correct and is takes forever to set up PW to get to a usable image.
Maxwell - is very quick to set up and get very good lighting etc and importantly a consistancy in your work, but at present, it does take some time to get a noise free image. Maxwell is also not yet able to cope with decals and is reliant on SW for textures so this is a problem as the SW texture mapping is very crude indeed. But in time this will improve I am sure.
PW is the orphan of SW add-ins - It has been left without any significant develeopment for the last 5 years and any bugs in it are just left there . I don't think it will improve much.
Maxwell is still in beta form and already I prefer to use it as my render of choice. It is at the start of its development curve and I hope that it will in the next year totally leapfrog PW.
As for the cost - $495 now or $1000 after release - $495 is a bargain, and at $1000 it is still a bargain but that is only after I know what it is capable of. For the unitiated, a demo version will be needed to convince them that a $1000 is a bargain.
Have you seen John Laynes renderings that he posted on the SW newsgroup - great stuff and he had only been using Maxwell for a week.
TTFN
Jonathan