Based on your facts, that there is no discernible difference in speed or accuracy, it really should make no difference. However, 5/8" change in brace height should make a difference in speed and accuracy, so you might want to test again after you've shot the bow for a while and see if you get a different result. In the mean time, I would start with 7 1/4", just because that's what Dan has told me works best on the Whip I bought from him, and I've never had any reason to want to change it.