Gems vs Plugins

Which one to use GEMS or PLUGINS?
This was a question i always asked and i have searched on the internet for comparisons between each one and the other

i can see that people prefer gems for the sake that it is the new future, it has obligatory versions other than rails plugins

But as for me, i only see gems useful in these two cases

1. when using code provided as gem outside of Rails, maybe with some ruby application
2. if you want to share code written in gem among applications

other than that, i see plugins better and much more maintainable for each application on its own