You cannot compare these platforms with musing.io
Musing.io is a Q&A platform, steepshot a photo platform (a bit comparable with Instagram), and so on.

They all have different purposes and different features.

If you'd ask about steemit.com in comparison to busy.org or esteem, … this is something different because these FrontEnds do not just show a part of the posts but all. So there you need to look at all functions. Some prefer steemit.com, others like steempeak for adding lots of statistics.