Pros: Well, it works. Once it's set up, it will automatically and transparently record all phone calls to a drive of your choice as long as the server program is running, which doesn't use a ton of memory.

Cons: First and foremost, the audio quality is terrible, even for a phone call. It's an 8 kbps MP3 file, and it's so muddy as to be barely intelligible. I couldn't get the WAV output to work at all (produced a corrupted/unplayable file).
Secondly, the user interface and manual are what you might expect from a cheap product from China. It's really unintuitive.
The data is stored in a proprietary data format in a folder that you can't specify (besides which drive letter), and replaying a conversation requires you to perform a query ("Inquire") to find the conversation, then choose "Backup" to save an MP3 version. There are no quality settings.

Other Thoughts:

Bottomline: The recordings are pretty easy to save, but tricky to play back. It's probably good enough to prove that something was said, but you won't want to just replay a conversation for fun, since you'll have to strain to understand what's being said.