Seems to me like medium is one of, if not their most popular size, because it seems like medium sizes sell out first. Personally, I wear medium diaps, being 6’ 0” and about 180 pounds. It doesn’t concern me at the moment because I stocked up over the holidays, but I can understand any frustration.
I did have an opportunity to give LFB’s (Little For Big) line of four tape diapers after getting a bunch of Amazon gift cards over the holidays. While the capacity is similar to what you’d get from say a Cushies diaper, they definitely feel a little cheaper in terms of materials. The one thing they do well is keeping the absorbing material in place, even after use. They’re a few bucks cheaper per pack too, but can’t match ABU’s value buying in bulk. If anyone’s looking for a suggestion to get by with, try the LFB diapers.