I'm very adept at unix cmd line, find, ack, locate, CDPATH, cmd history, and friends. I spend 10-20% of my editing time at the bash prompt. So much so i aliased :e to vim
Having never got the "gui" file managemnet tools i cant say for certain but i wonder if power and productivity gains one sees from truly learning vim can be reproduced by truly learning cmd line.
After I open a file once it is in my vim and or bash history which means opening it again is only a couple keystrokes.
I use <ctrl>6 and multiple (3-4) non-overlapping terminals (with text mode vim) in various directories. So "jump to file foo.bar" is often look at the vim/terminal to the upper right or <ctrl>6 or :e<space>f<up><enter>
Don't remember what this does excactly but it's in my vimrc and might have something to do with it.
"freakin awesome file completion set wildmode=list:longest
I also use this form of "history"
bind '"\e[A"':history-search-backward bind '"\e[B"':history-search-forward
I also use ctags. Usually I want to look things up by symbol name, not filename, though it's trivially easy to make a script that generates a tags file of just filenames too. (And :tag also supports tab completion.)