While there must be some, it's hard to imagine that you'd notice it.  System resources is not the issue under W2K/XP that it was under Win9x.  Nor does it affect Poser memory significantly - it uses Poser Python (PPP/P5/P6) (or P4PyE for P4 which uses zero Poser memory) instead of the library panel, so as the latter is very image intensive, it seems unlikely to increase memory usage.  (The library manager will still occupy memory of course due to Poser's total lack of any real memory management.)

And PBIIalso no longer resides in memory between Poser sessions a la the original PB, relying instead on the included Hogsoft Hub which uses a very, very small memory footprint in your Windows Tray, but can reload PBII in a click.

Trade this against huge user workflow improvements, and modern mouse support - thumbwheel, right-click menus, etc.  (If you have 2 monitors, PBII can reside on the other monitor and always be visible.)  And anything has to be better than that ridiculous near-circular pop-out menu selection at teh top of P5/P6 library panel!!!