John, you can't discount muscle memory.
I've logged a zillion hours on Rapture, and when Rapture Pro came out, even after many hours of checking it out I felt the interface was a major step backwards. However technical glitches notwithstanding, I've started to wrap my head around the interface and am finding it's just...different, and with some helpful improvements. I suppose that once I've logged a zillion hours on Rapture Pro, I'll find Rapture klunky.