Amazing is an understatement. The biggest complaint I usually hear about wireless networking is range (and when people complain about reliability, they almost always mean range), and DD-WRT offers several solutions to this.First of all, DD-WRT allows cheap, ubiquitous routers to serve other functions. Wireless repeaters cost $100. Wireless routers cost $50. DD-WRT lets you turn that $50 router into a repeater, among other things. So if there’s a dead spot in your house, you can pick up another WRT54G (be sure to get the WRT54GL version if you’re buying new; when buying used, you want version 6 or earlier, and version 2 or so is probably the best), load DD-WRT on it, use it as a repeater, and save 50 bucks. Some of the used units on Amazon or eBay already have DD-WRT loaded on them, which can save you some effort.
Second of all, once you load DD-WRT, you can connect to it, click on Wireless, then Advanced Settings, and scroll down to TX Power. The default value is 28. You may want to adjust that.
I was also happy to see that once when I configured my second WRT54G as a wireless bridge, the computer I was using to configure it gained Internet access through it. So a DD-WRT-equipped router can do double duty. If you have a video game console with an Ethernet port on it, you can put one of these routers in the same room with it, run a cable to the device to put the game system online, and at the same time configure the router to serve as a repeater, strengthening your wireless signal. So not only do you save $50 by not having to buy a repeater, it can also mean one less wireless card you have to buy.
The one thing I’ll say about DD-WRT is that when you load it, you need to take precautions. If you follow the instructions, loading it is a safe procedure that only takes a minute or two. But if you don’t follow the instructions, it’s possible to ruin the router. You never want to change firmware using a wireless connection; use a computer connected to a wired port. And with my particular router and the version of DD-WRT I was loading, I had to use Internet Explorer. For some reason Firefox has difficulty getting this particular job done. Also you have to load the factory default settings at one point or another during the configuration. So read the documentation at least twice and make sure you understand everything before you proceed.
I like DD-WRT a lot and I plan to load it on the WRT54G that I have connected to my DSL modem very soon. The main benefit I see is being able to crank the power of the signal up a bit, but there are plenty of other goodies in there that I may end up using. Perhaps more importantly, my WRT54G stopped working with DynDNS at some point, and Cisco/Linksys doesn’t seem to be revising the standard WRT54G firmware anymore. But DD-WRT has an active community behind it, so if something changes, I’m confident that there’ll be a new DD-WRT to take care of me, whether I need it next year or five years from now.