Another observation of mine, I research a lot of code and have a very large online presence using OSC. This contrib is one of the most powerful I have seen out there, (for my needs). This contrib can be manipulated to do much more than just a parts filter. The 2.3 version using ajax is quite the catch..... I have about 10 hours hack time so far and like very much what I see. I did not know the power of setting cookies and filters until now. I will be harnessing this power further and test my results quite soon. This add-on solves many categorie problems when you get above 900 plus categories. Allows a very precise navigation of your site by stepping in without huge database pulls. Seems fast but testing further is needed. Add a little memcache and this could be real big for me.