They look great! I do have one thought though... I understand the interchangeable factor of leaving the plants in their original containers, but I think if you and planted directly in the hollow logs, the logs will supply nutrients as they break down. (But they WILL break down so they won't last as long.) I would add extra earthworms and coffee grounds in there to help balance the nutrients and lime or crushed oystershells to neutralize the pH.
I was never inclined to pick up the hollowed out logs people put out after cutting down a tree because I was always concerned about termites and other bugs (as well as what people might have used to try to "save" the tree before cutting it down) but looking at your photos, I want one!
Maybe I could use DH's weed flamer to burn out the inside of the logs first... Hm, hmmm.