So, first off, this thing is expensive and I personally think there are WAAAAAY too many self-congratulatory reviews on the internet for expensive products. Like everything else, this thing has pluses and minuses. If you want the short-but-sweet version: it works, it has some nice features, several drawbacks and I think it's too expensive to give it a sound recommendation.
Very small form factor
Stainless enclosure is nice
PID controller eliminates overshoot (but is of questionable utility)
Works for natural gas or propane setups
PID seems unstable
PC software is clunky, poor user interface, and only runs on Windows
Communications cable is overpriced
Programming your own mash steps is tricky
PID controller has insufficient documentation
Installation not straightforward
Some additional information that I've gathered and think is useful:
The PID they're using appears to be the venerable Love Series 16B. At least they appear similar in appearance and they're also using the same software! The "TOP-Link" software has the same appearance/look/feel of the "Love-Link" software from Love Controls. This is very disappointing to me because this software is a stinker, only runs on Windows and has a craptacular UI.
I'm reasonably confident that they're also using this Fenwal 120v ignition module (or a similar product from the same manufacturer), and here's an appropriate electrode.
I'm not saying this whole thing is a piece of cake, but I do think it's overpriced but by how much is hard to say. The PID is about $90, the ignition module is about $200, and the electrode is between $20 and $50. So that's at least $350 before you add wiring, a case, a solenoid valve, etc. It retails for about $575, so I guess it's a matter of how much you like doing this stuff and how much it's worth to you.