Poser Pro was just a bad idea all around IMHO.  Maybe a Poser Pro Render Tool set for render farms would have been a good idea, but when basic features aren't even the same and the upgrades aren't released at the same time how can we know which we need?

(As far as I know their features are mostly the same.  When P8 comes out though, it will be ahead of PPro in some places and yet still behind in others.) 

Trying to upgrade two programs with staggered releases just to keep up with every new feature is a lot to ask of your market base.  I 'd prefer the way Caligari marketed its programs in the '90s.  The Pro version cost $1995, while the hobbyist version was about $300.  Each upgrade to the hobbyist version brought it up to the level of the previous pro version.  Pros got the immediate benefit of the program's development, while hobbyists always knew what would be in their next upgrade.