I'm contemplating on getting a Linksys WRT54GL and flashing it with either dd-wrt or openwrt. At the moment, I leaning towards dd-wrt because it seems easier to configure and has comprehensive documentation on website. Openwrt on the other hand seems flexible but the documentation on the web is more on using command line.
Just wanting to know your experience with dd-wrt or openwrt so I can decide which one to use.
I too have been running dd-wrt on mine for a few years. As I recall, it was very easy to set up, I pretty much just configured it and left it - it's been running great. I don't recall needing to reboot it pretty much ever (of course, it has been unplugged/moved a few times).
If you don't already have a modem that does pppoa half bridge / ip extension. I would recommend getting a TP Link TD 8840 or a DSE XH9949 for the modem (assuming you're on a standard ppoa ADSL connection).
For the router you don't have to stick with the WRT54GL there are newer models from other manufacturers eg Asus which are similar chipset with more memory and cpu power.