I'm quite happy with 12sp, the only thing I dislike is the production of 9 and 10t cogs requiring different cassette freehub bodies. Don't know where people live that they need such extreme gear ranges but if you really need more gearing than an 11-48 or 52 provides with a single chainring then get a second chainring. Otherwise its just a move to make a decent system obsolete for the sake of cramming that 9t on there. If you really need to redesign the freehub, make it better in every way so its worth switching, not just to keep up with the latest trend.