I have no doubt that OpenWrt is technically superior in every aspect over any off-the-shelf/consumer-based wireless router's factory-default firmware. Beyond using it for myself, OpenWrt is something I'm tempted to also load on my friends', families' and clients' wireless routers as it offers a number of benefits, including various bug fixes and extended support for otherwise limited or unfinished features. Unfortunately, by itself, OpenWrt isn't exactly ready for the consumer/end-user market, at least not until the general population knows how to use SSH and a Linux/Unix shell.
This is where X-Wrt comes in. While I'm not saying that it will allow any person with any level of computer experience to properly setup their wireless/home network, it's definitely better than what OpenWrt provides by default. Compared to the factory-default interfaces in just about any off-the-shelf/consumer-based wireless router, X-Wrt is feature-rich, stable, and easy to use.
If I see any usability issues with this enhanced interface, it's in the large number of options that are available. However, everything seems well-labeled and organized, and anything not understood can probably be safely ignored.
Some of my favorite features of X-Wrt include visual graphs: Dynamic line graphs of CPU activity and network traffic, and bar graphs for RAM usage, tracked connections, and disk space.
If you're not already using, or are not all that familiar with OpenWrt, I'd suggest using a direct firmware link from method #1 on the X-Wrt page. This will get you setup with a default version of OpenWrt and X-Wrt in one operation.
While method #2 will work with an existing OpenWrt install, it isn't very efficient, especially if an older version of webif is already installed as an integrated part of the firmware. That space cannot be reclaimed without changing the firmware (e.g., method #1.) If you have a Linux installation, consider building your own OpenWrt with the latest X-Wrt integrated - see OpenWrt's ImageBuilderHowTo for details. While you're at it, you probably want to include the nas and wl packages, and any additional packages that you will want, such as tcpdump and any dependencies. (With the way that OpenWrt works (read about SquashFS), including packages as part of the image actually saves space, compared to installing afterwards.)