My gripes are mainly aesthetic, though I will say that reverting to v6 felt like a huge weight has been lifted for me personally. Can’t speak for features, as I rarely do much beyond sending basic emails etc. Though the workflow and interface continued to feel uncomfortable for me even after several days of use.
That said, perhaps the new version will come with an option to revert the layout to v6 so that users such as myself could get the best of both worlds?