I recently added a HDHomeRun TV to my home network. It's made by ElGato, the InterCappedObsessed company that makes EyeTV. But it also supports Windows 7 Media Center if you swing that way.
I've been an EyeTV user for a very long time. (See Appreciating EyeTV, One Week with EyeTV, and EyeTV with Turbo.264 iPhone Export Error: Resolved for earlier posts about this subject.) I decided to get the HDHomeRun (replacing my EyeTV Hybrid) so that I could watch TV from any computer on my network, and also to retire the Mac that hosts the EyeTV Hybrid. The HDHomeRun, you see, is a standalone device that streams live TV to any computer that has the software installed.
I'm disappointed that it requires the EyeTV software, as good as the package is, and I'd prefer a device that just worked with QuickTime by itself. Because it doesn't work that way, in order to stream to an iOS device, you have to have a host Mac running EyeTV act as an intermediary. ElGato makes this clear in their advertising, so it's not a complaint but a wistful desire on my part. (I don't record TV using EyeTV, but it's worth noting that this is another case where a host computer is required.)
Setting up the HDHomeRun is easy, but you have to repeat the process for every computer that will access the device. This seems like another missed opportunity for a better user experience, but thankfully it's more silly than it is burdensome.
Performance is acceptable, but heed ElGato's warning that network bandwidth is very much a factor. With a slower Wi-Fi network you'll find that TV frequently stutters and pauses. A less obvious performance bottleneck also occurs if the computer you're using is memory or speed constrained. Although EyeTV will run on less powerful computers, I found that performance was worse when using HDHomeRun as compared to the EyeTV Hybrid.
Although ElGato doesn't make it obvious in the meager "tech specs" that they publish for the HDHomeRun, it's a 100BASE-T network device. It seems to me that a bandwidth-hungry box like this would be better with Gigabit Ethernet, but as I said above, perhaps the performance is more impacted by the speed of the host computer than transmission constraints.
All in all, I'm happy with the convenience and flexibility of the HDHomeRun, but I wish that El Gato would make it fully functioning standalone device. If you're already familiar with how PC-based broadcast TV works, and its quirks, you'll probably be happy with it too.