I've been enjoying my first TB purchase, a black dyneema S19, for a couple of months, and am getting an order ready for an A30 for my husband (hopefully ASAP once new products are announced next week!). He is a very organized person and wears size 9.5 shoes.
I see from the packing cube page that WF small packing cubes would take a regular pair of size 12 mens shoes. However on occasion he'd like to bring low ankle hiking boots (e.g., Asolo Agent GV MM Wool - Zappos.com Free Shipping BOTH Ways), which I think would be too big for the WF small packing cube. Most of his trips don't require hiking boots though.
The advantage that I can see of getting the WF cube over the A30 end pocket cube is that there might be more room for stuff sacks. I could of course get both, but we already have one travel laundry stuff sack that looks to be a perfect fit for the end pocket as well, and of course if I end up borrowing the bag the end pocket cube will be way too big for my shoes...