So there's only a couple of issues I've discovered with the Linksys Wireless-B Media Adapter. The control is really good, and the browsing works great.
However, even when you're not actively serving out files from the PC to the adapter, the service that runs in the background regularly chews up CPU cycles, hitting 35% at times. Ouch! And guess what needed to be installed before I could install this? Windows .NET Framework v1.1. Gee, I wonder if that's why it's slow?
I regularly kill the service if I've booted and know I'm not going to be using the adapter.
The other annoying thing is the service doesn't show up in the Services list, so there's no way to stop or restart it easily. I've resorted to killing it in Task Manager, but then I have no way to get it going again--running the Linksys's "Manage Shared Folders" application doesn't restart them, neither does launching their EXEs directly. In fact, launching their EXEs gives you a (Microsoft) message that "You can't launch this service this way, you should do it from the Services tool".
Apart from those concerns, it's working great--we have to keep the CDs hidden away in a closet, or one or more of the kids gets into them and starts opening them, so having a way to stream MP3s from the PC to the stereo is great. It was certainly worth the minimal cash I spent on it.