That's a nice post :)

A few months ago I was also looking at A123 cells, but the thing that I don't like is that they have such a stupid size. I would really like to use them in some of my cars, but they just won't fit. My second idea was to use them in an E-Bike I wanted (and still want) to make, but as these cells only have a capacity of 2300mAh I needed to buy a LOT of them to solder some in parallel. I'm not sure, but I thought I would have needed 48 of these cells to have a reasonable runtime. At that time they costed about $7/piece, which would be $336 for all.
Anyway, my finding was that I could better go with LiPo's as they are a lot cheaper, and I could also use them in my cars. After some research I saw that I could buy these A123 cells for I thought $4/piece, which is very cheap, but they were directly from China and I didn't know anything about the quality of those A123 China cells. Then the idea "died"...
After reading your post I'm really considering buying a DeWalt pack, and some cheap A123 cells from China, to compare them and to get my first experience with A123 cells.

Could someone post a link of those 10Ah cells? That sounds very interesting!