For me Publer do one thing, and the tool do it perfectly !! Post in social medias, this is all what we need at the end of the day. Not extra features for which we don't give a ... and which complixify the user interface.
The interface is really simple, and for me it's important. Not like other competitors interface where you can't find what you need (just post or schedule posts). This is what I liked on it.
To link the page is really simple and don't bug for me (in all other LTD I took I had bugs on this side and had to contact support).
To be able to add team members, which is important for me (I have community managers) for which I need to give access to post.
We can link several Fan Pages and Groups (you need to be admin), and post on all of them.
We can change the timezone which was important for me (i'm not living in the same country for which I have to schedule, so I don't have to do time conversion and wast my time).
What this LTD need to be perfect ? a mobile app to be able to link Instagram and post on instagram from the app (like competitors).
It need also visibility on the future (Publbox which I bought on Appsumo has closed some weeks before, I hope for the founders this service will go in the right direction and they will do the right moves for their marketing).