I have bought three Poser 8 licenses, for my 32bit machines.  My two 64bit machines have Poser Pro licenses, and I will wait for the new Pro release to upgrade them.

If the benchmark tests don't show an improvement of Poser Pro (rendering at 64bit) as opposed to Poser 7, then the tests don't reflect my world accurately.  I tend to load scenes with geometry, complex material node work, animation keys, and light/shadow effects.  On occasion when one of the 32bit machines succeeded in rendering a wallpaper, it took much longer than the 64bit machine, probably just because the 32bit box was running near the cliff edge.  But often, the 32bit box with 4Gb RAM just chokes and dies.  In all such cases, the 64bit renderer is immeasurably better, since it becomes a question of  "fail" or "succeed".

I recall that this was rendered at 2560x1600 pixels on a quad-core 4Gb 32bit machine:
http://www.renderosity.com/mod/gallery/index.php?image_id=1925026

...but rendering this at 2560x1600 drew 1.4Gb just for the Poser Pro executable, and 4.4Gb for the 64bit FireFly:
http://www.renderosity.com/mod/gallery/index.php?image_id=1924625

(how can I post an image/thumb-link directly from my gallery?)