I've made this King Arthur's Honey-Pat Pain de Mie twice now, using my brand-new pain de mie pan. The bread on the left is from my first attempt, while the bread on the right is from my second attempt.
The first time I followed the recipe exactly as written. The bread didn't fully rise to the top of the pan, but I think that was due more to my elementary shaping skills and that I could've let the dough have a longer second rise.
The second time I made the bread, I substituted 160g (about 44%) of the APF with whole wheat flour, some of the honey with maple syrup (as I'd run out of honey), 10g (about 15%) of the butter with vegetable oil, and added a few dashes of cinnamon. I also used 230g of water. The bread rose in the refrigerator, because I didn't have enough continuous time at home for it to rise at room temperature.
For next time, I would increase the water - the dough seemed like it could've used more water, and I might have killed off some of the yeast by using boiling water. I thought the oats would protect the yeast in the bowl, but perhaps not, given the lower rise. The second batch still had a fine crumb, and is still quite soft and very tasty. The kids love it.
I might have to buy another pan, because it's so yummy, the loaf disappears quickly!