I worked on Ubuntu Touch (specifically convergence) for a few years.
I think it's really interesting what Apple are trying to do (with Marzipan, pro apps for iPad, desktop level SoC's) but I think they still have a couple of years work ahead of them. It's not an easy task, especially with so much legacy.
Getting Adobe and Autodesk to rewrite their flagship software for iOS was quite a good win, though I still wonder how those compare to the desktop versions