Maybe its improved...
I went to a bunch of talks about Sailfish and Mer at FOSDEM this year and wasnt too impressed.
Thier "SDK" was doing all sorts of total nonsense like having thier emulator, inside a linux virtualbox, speak to a qt creator plugin, on the windows host, via a shared folder. WHY. Of course this totally robust creation failed, the emulator was slow, the SDKs autocomplete and designer didnt work, and thier dev was unable to actually demo anything.
Maybe its improved... They guys did seem enthusiastic and I could tell they did actually want this to succeed, as as a QT developer I wouldalso love to see it being used more for precicely this.