Carrara 6 is pretty inefficient with memory (worse, I believe, than Poser 7, but possibly on a par with Poser 6).   It does also have the problems with dials that Miss Nancy mentioned.   For most Poser-type characters, dials load as sliders, with values available from 0 to 1.  Any value to the right of +1, or to the left of 0, has to be entered manually, which is unnecessarily restricting.   

There are also no dials in Carrara for controlling movement of joints.   Movement is done directly in the scene, with the scope of the possible movement restricted by "constraints".   Some characters are constrained, by default, to be unable to bend their elbow joints beyond ninety degrees.   You can switch between various settings of constraint, but a set of dials would seem to be a better solution.

There was a thread on DAZ, where a new Carrara user properly expressed dismay at the shortage of dials and was slapped down by somebody with the "dials-are-strictly-for-the-groundlings" attitude.  No doubt, that particular somebody daily curses the designer who invented the car ignition-key and rendered obsolete the purity of the cranking-handle.

As a C5 user, I was able to get C6 quite cheaply when it was launched and I have used it a fair amount since, but I'd tend to turn Miss Nancy's remark on its head:  Poser is good enuff IMVHO that C6Pro is not always (or often) needed.   I am quite glad that I didn't need to fork out the full price for it, because I don't think it's worth it.   If I want to use a different render engine for Poser, I am much more inclined to try Vue.