It was improved in Poser 10 actually. It's mostly the only thing I use for grouping. Sometimes I'll group in zbrush, but that actually winds up being more work than its worth if it's something with a lot of groups, cause I just have to go in and duplicate, rename and delete all the groups in poser, so I might as well save myself time and do it all in Poser to begin with. The mirror function is a huge time saver.