Honestly, the new beta still has bugs and I'm sure James wants to get the best stable release he can. A new beta just came out in 2 months. That's better than some other dashboards can say so you know he is still developing for it (UX is a one-man project). You are still welcome to try the other dashes but I, personally, wouldn't. UX offers alot in its current state.
To me, UX has alot of potential and nothing else has come out lately to make me want to replace it. A new release will come and build 1218 is still pretty stable (besides FTP; there is still XBMC). If you read the Quick Note in WIP subforum you would know that James has been busy with Real Life lately too. The new WIPs may have brought new features and such, but I would hate for said features to be overshadowed by posts complaining about the bugs.