I've seen that cubic loading idea show up in other spots and while the idea is good I think you're working with too small a database of model designs to accuratley set the guides for the categories at this point. That's where the downfall is. It's not the idea but rather just that you don't have enough data and reports of what the models in each category are actually LIKE to fly.

Like I mentioned above a given model will take to the air under a very wide range of wingloading values but the fun aspect vs adequite performace vs pig to fly occur at various points along that scale based not only on the cubic loading but also on the power of the engine used.

I seem to remember that Thunder Tiger made a 40 trainer and if so then I've helped a student fly one. Terrible plane with only a so so glide that didn't seem to uderstand the idea of forward motion too well even with a not 40 up front. I don't know the cubic loading of that one but if it's in the same 8 value or even up to a 10 then the system needs to be fudged some more or reviewed to determine the missing elements.

I also ran through some numbers for my own models and they seem to fit not too badly at all into your current ranges shown in the chart on your site. My 89 inch Flamingo Old Timer comes in at 1180 sq inches and 5.5 lbs for a CWL of 3.74 and it certainly does fly as lightly as this suggests. My old sport power Quickie 500 with the 25 at 52 oz comes in at 8.04 and that fits within your current numbers for a nice sport model. My 1/2A rudder only sport model at 255 sq in and 19 oz hits the scale at 8.31 and I'd say that's not far off. The glide of that one is nice but a trifle quick and that fits with the idea of the range.

A suggestion. Lightweight 3D or the old school boom fuselage fun fly models of all types will obviously fit within the low range and you may want to add them there.

Or better yet, if enough folks provide model data and some accurate feedback on what the models fly like with comparisons to some well known samples as benchmarks then I would suggest you remove the name categories and instead include notes on the type of performance that can be expected for the ranges of cubic loadings. My 89 inch old timer is sure not a parkflyer but it floats as nicely as a Gentle Lady glider. So the numbers suggesting a style of flying may be more accurate than the types of models.