Your grit is laudable, Dale. I too have used nano and a bazillion echo statements directly on a server. My reason for the OP was that Flash Builder 4.5 (based on Eclipse) appears to offer all kinds of automatic code generation and data integration (not to mention code hinting, declaration lookup quick keys, debugging of both client and server code, etc.) which would likely reduce a LOT of the tediousness in coding and speed up my work. Admittedly, I am quite wary of auto-generated code, but I'd very much like to focus more on the high-level concept and less on the nuts-and-bolts of code.
Not long ago I went through the trouble of setting up Eclipse as my IDE on an Ubuntu workstation. I found that it really sped up my development. In particular:
save files to webroot on the local file system means instant availability on web server
Eclipse offers quick keys to lookup declaration of functions, constants, etc.
Eclipse offers code hinting and code completion, code formatting
Eclipse integrates with both SVN and GIT
I can debug my PHP code in either CLI or apache context -- no need to added echo or log statements to understand what is going on in code.
separate machine for PHP dev means my windows desktop doesn't get bogged down with mysql daemon, apache, etc.
I wasn't easy to get the debugging setup working, but I think it was worth it. The code hinting and lookup stuff is a real time-saver.