I had no idea there was a Poser to Lux exporter! Downloading now...

My recommendation: get DS4, get the Poser trial version, and try both.  Then pick the one that you're most at ease with.

A lot of Poser content works fine in DS4, but as was mentioned fancy Poser materials won't work well (if at all), and Poser dynamic cloth won't work period.

Best of luck with your choice! I moved fro DS4 to PPro, PPro works best for me,  plus I'm saving up for Cinema4D and being able to bring my content into Cinema is important for me.