>>51
vim's interface to regex is fast as fuck once you are good with it. And it blends well with the q key sequence macro command. I use vim to edit hundreds of buffers concurrently, but I don't recommend it that well if you are fine with using a mouse to navigate your recently accessed files. I have a key mapped to :buffers<CR>, which lists all open buffers, and :b n can jump to buffer n, or :b er.y can open scanner.y if the match was unique. Using this and :n line number jumping is sufficient for navigation for me, and I use piped commands of find and grep to look for what I need.
Finding the definition of a function can be difficult because that requires a bit more awareness of the syntax that what you get with find and grep. A complete solution would take some language specific support and I am not aware of a built in feature for this in vim. It wouldn't be that difficult to properly implement. A command line tool could parse a specified set of source files, and construct and keep up to date a small data base of definition locations. The program or server could then be queried with identifiers from certain locations in the project, and it could then print the file and line number of the definition. Then a vim script could handle sending the identfier under the current cursor position to a command invoking the program, and then read the path of file containing the defintion and the line number. The file could then be opened, and then it could jump to the line number. The beauty of this is that you wouldn't have to use vim to take advantage of this feature. Any editor that supports automated shell commands and some kind of interface to variables like text under the cursor can do it. I would be surprised if an open source implementation of this didn't already exist by now. But I haven't had enough of a need for it to look yet.