Paul,
As with the FF artists, all models are rated the same. Fred Abler and I agonised about this some years ago, but decided that there is simply no way of formulating a system to grade models.
Everyone knows an "easy" model when they see one, but actually categorising it is a whole different thing. You can't grade according to the type of model (saying chairs are easy compared to cars) because what about some of the very fluid modern designs or a Louis XV, covered in mouldings and gold ormalu? Nor can you go on the number of polys (Just leave the arcs and circles at their default values and you can end up with tens of thousands of polys in seconds). And it would simply get too argumentative classifying each model individually...and somewhat subjectively.
The site actually says 4 downloads for 1 upload, but I've never had cause to test it. Jo Spo won't be able to upload a cube...because I won't approve it. Remember, it's not an automatic upload as on certain other sites, everything goes through QC. I can (and do) edit models that haven't followed the guidelines correctly, just as I have refused a few models that were too far wide of the mark (usually lousy quality or obvious copyright infringement). It'd be just as easy for me to simply delete extra configs that I thought were milking the system.
I'm hoping to put up a clearer list of guidelines shortly, to minimise such problems.