I finally had the opportunity to load Tomato on my WRT54GS v.3 over the weekend and this is absolutely the best firmware I have come across to date. The interface is clean and offers something DD-WRT does not: realtime bandwidth monitoring from the web interface. Thus far, it has run very stable. There is also a noticeable difference in response times.
A little word of caution, though. After my installation, I HAD to reset the router (not power-cycle) via the reset switch. If you notice any issues of your password now working properly, the device more than likely just needs a reset. Another way around this problem is to restore your router to it’s factory defaults prior to the Tomato installation.
The Tomato firmware is available at http://www.polarcloud.com/tomato.