Ranked in these QuestionsQuestion Ranking
Pro Good plugins
Noecomplete's author has made some very good plugins which are also actively maintained.
Con Active development has stopped
Neocomplete is no longer under active development. It's considered deprecated in favor of Deoplete, the newer and async version.
Con Neocomplete does not work with all Vim versions
It requires Lua support and the Lua driver.
Con No support for Julia
There's none to be found.
Con Autocompletion can be slow
Some users have reported that Neocomplete's autocompletion can be slower than other alternatives.