I'm glad my modesty leaf was enjoyed!
On more careful examination, the gathered dress in XL actually turns out to be rather bigger - wider - than last year's version in L. It's going back because it's too big on me. I'm a generous high street 18, so that's really quite big and larger than Toast dresses usually are in XL/18.
I thought about ordering an L, but decided that the lines on the pattern don't work for me with this shape. The dress shape is droopy over curves in a flattering way which worked well with the leaf print. But on this the lines make a sort of graph of the draped curves, which isn't good. 'The lines are just too liney, mummy', says my focus group. Also DH didn't like the blue in the pattern, though on that he's wrong as usual. At these prices, things do have to be just right.
If I have a conclusion there, it's that you probably want to size down when ordering this dress (unless at the edge of range of a size) and that the lines may not appeal to you unless you want boobs emphasized.