I've always used the NetRW plugin for file management. NERDTree was too sluggish for me (but that was 6 years ago...) NetRW does all I need to: tree view, open file (same buffer, same side-buffer, new buffer, new tab), create file, delete file. And it comes with vim's distribution.

Anything else I need I use a real file manager, like Midnight Commander (usually inside a vim's tab) of vifm (a very vi-like file manager).