I personally have 2 in my household and know 4 other families...

I personally have 2 in my household and know 4 other families that also have them and we all can't live without them these days for the piece of mind it give us. The battery also with our first one ran flat sooner than we would have liked initially however after consulting with the Spacetalk customer care department who have been utterly fantastic that was solved ages ago so as to not ping the location every 2 seconds and also make sure you have the latest firmware updates (they have constantly released these over the year). Everything runs as planned. Is it perfect, no. But neither is the brand new iPhone I purchased but as I said for the intended need of the product and the independence it gives plus our piece of mind, there is nothing else comparable, which is why all these Telco and bricks and mortar stores are picking it up.

As for the reviews you always need to take them with a grain of salt. People that post reviews fall in 1 of 2 categories. They are either utterly amazed by their purchase and it exceeds their expectations or they want to have a whinge, most people fall in the later. That site had 11 5 stars and 15 1 star for total of just 38 reviews. They have sold 20k of these so that is 0.19% miniscule indeed. I'd personally give it a 4-4.5 star. They have indicated that a new version will be released at some point which should iron out any issues, just as most tech companies do over the years.