Miloa,
You need to stop thinking only in terms of % ABV. Given an acceptable environment, yeast will consume the sugar available up to their tolerance level. Saying natural yeast takes it to 10-11% doesn't mean much without the final gravity. Without FG, we don't know if it really did conk out at 11%, or if that's just the potential of the cider you had to begin with.
Flavor of a product has a lot more to do with the overall ingredients and the residual components left after fermentation, than it does on just the yeast.
Take Homebrewer_99's recipe (which sounds delicious by the way and I'm going to try it). The corn sugar provides an alcohol boost, but doesn't provide anything in the way of flavor of the final product, nothing except burn.
The molasses in the dark brown sugar and the honey lend a carmel-like and honey flavor and scent. With a SG of 1.126 at the beginning of September, and currently just over 16%, we can calculate that the gravity is probably down between 1.004 and 1.005. With K1-V1116, thats doing well at almost 97% attenuation, but at only 3 months old, it may not be entirely done yet.
And while the residual sugars and flavorings from the mix of ingredients will help make this drinkable younger, at 16% it'll probably still be a year for the burn to mellow and all the flavor profiles to meld. My guess, at x-mas 2010, this will be putting all Homebrewer_99's houseguests UNDER the tree!
With your 20# of sugar you're looking at close to 35% potential. Nothing out there will ferment that out. Even distillers yeast drops out at 23%, that's why they distill to reach the higher ABV content.