Afaik* one main problem on Sailfish is, that there's no nice way to get an x-server or any x-forwarding running.
In Easy Debian this is done via xephyr, which almost has no influence on performance at all as long as you don't need hardware accelerated graphics. In Sailfish you'd be stuck with some vnc solution, which generally works fine, but is slow and conceptually ugly.

just mentioning:
There's a typo in this blog post:This needs to be:In principle you should already be able to grab a random Easy Debian image, chroot into it, install some vncserver (e.g. tightvncserver or vnc4server), configure it to create a desktop matching your phone's display resolution on $DISPLAY :1, and run it.
Then you can connect to this desktop using whatever vncviewer Sailfish offers by specifying the correct display (in my example :1) and port (default port should be in the server's documentation).


*) Which might be totally wrong due to mere hearsay on my side.