I'm the maintainer of amVim.
I don't know if you tried amVim. It supports Visual and VisualLine.
Also, you may find it handles detail behaviors of Vim much better.
g; and W/E support would be nice (as someone said on this thread, everyone has a different subset of Vim they use ;-) )
Oh. ex-mode is not something I'm planing to implement. They are often a lot easier to do with Cmd+Shift+P.