Hey Tim,
I am using a Tempest 15A on a 1/2aish size airplane and have used a Bad A$$ Rebel 45A on a P-40 with success. Got a little more focused with Phoenix Edge Lite 50 (PEL50) in Airplane mode on my Profile Oriental but was not happy with the response time. Based on some of Paul and Dick's work with Paul Emmerson, I did some bench comparison between airplane and multirotor modes and had good results with the PEL50. Glad to hear that brake has been added to the multirotor mode by Castle. Just need things to dry out a little more to get some testing in.
John