I think if you have a very unevenly sized set of thighs, then you might go bonless because you can cut them to a uniform size easier. I have always done bone in though because I think the bone gives structure to the whole thing, but since I super tanked at the last practice cook, and the guy who scraped his skin down and did the butter bath thing took 1st place, I was thinkin I need to at least try it once.