My verdict: you get what you pay for. SnapStream PVS is reasonably priced, for a reason. SnapStream PVS falls between several chairs. It is proprietary software, and thus can not be tinkered with under hood. MythTV, for example, has a plug-in architecture with different modules for weather forecast, games, digital photos, audio, etc. It is unlikely that SnapStream will offer any of these things in the near future. Also, SnapStream PVS is far from plug-and-play. Each PC configuration may be slightly different, and may expose different bugs. The software encoding is CPU-intensive, which means potentially skipped frames and hiccups, depending on the encoding complexity of the program stream. This uncertainty makes or breaks a product for the novice user, who simply wants something that "works". The feature set is packed, even overwhelming, but the instability of the software does not belong in a 3.0 product.
I recommend buying a stand-alone PVR if you're going for the "coach-user experience". There are far fewer variables, and you don't have to worry about compatibility problems. It is an appliance, and behaves as such. If time is money to you, then it will pay for itself over the years. On the other hand, if you're going as cheap as possible and do not want to tinker with Linux, then SnapStream is for you. Bear in mind that you should have as powerful a CPU as possible. As demonstrated by the beta software, SnapStream will offer hardware encoding support in the near future. Of course, if you start upgrading your PC specifically to use SnapStream, then you might as well go the route of a stand-alone PVR.