I use NERDTree and it's not even remotely close to Command-T (or PeepOpen, which is pretty much the same thing).

NERDTree is great for browsing your project and managing your files, but for opening files (when you know their names) you really can't beat the speed of Command-T/PeepOpen. They're in another league.

I don't know how people work without it.

I use vim project. I load all my files in the side pane, and I search with / the file I want to open.

http://www.vim.org/scripts/script.php?script_id=69

Fuzzy Finder is also very useful http://www.vim.org/scripts/script.php?script_id=1984

not nearly as much as command-t as it will only look for files in the current folder instead of going recursively down all folders

Not true. FuzzyFinder does search recursively.

It can, in fact, search pretty much anywhere in vim (from the docs):

        - buffers 
        - files 
        - directories 
        - most recently used files 
        - files around most recently used files 
        - most recently used command-lines 
        - bookmarked files 
        - bookmarked directories 
        - tags 
        - files which are included in current tagfiles 
        - jump list 
        - change list 
        - buffer lines 
        - quickfix 
        - help

:FufCoverageFile is what you're looking for.