Once a ubuntu phone turns up that supports docking, as the original concept video shows, I'm all over it. Until then it's just a niche mobile OS with a restricted number of apps, and likely too many bugs.
To be honnest I have no idea if Microsoft Continium or any player will release something like that in 2015, any news ?
UI-wise it'll look similar to the average user, but it's a pretty different approach.
Maybe things will change in a few years as ARM/Snapdragon/etc processors continue to improve and phones get more memory, but for the time being I think MS's approach to phones + large monitors is preferable.