I don't have a need for a gimbal feature, just thought it would be a neat thing to have in case. I had done lots of searches on creep too with any ballhead and did not find anything negative about the GP. Ultimate model, yes. Acra-Swiss B1 yes. Kirk yes. RRS didn't have creep issues but more ergonomic issues, political association issues (which do not matter to me) and being over built issues. Its heavy too.
So the Z1 and the GP are still the finalists. I know of Markins (how could one be on nikonians and not? Its the darling of the crowd around here) and just have no desire for this ballhead. It too gets great ratings, but I'd prefer to go with either the A-S Z1 or the GP. both can be returned simply if they don't work out.