SmartID's WiFi Detector works

There's been a lot of grumbling (here and elsewhere) about how awful Kensington's new WiFi Finder is, and how it doesn't detect closed networks or 802.11g, or distinguish between cordless phones and WiFi. Well, we've been playing with the other WiFi detector out there, the WFS-1 from SmartID, and can attest that it works pretty well, at least for us. Over the past month or so we've used it all over New York and San Francisco, it picked up WiFi everywhere we expected it to, and in plenty of places we didn't (like on the corner of Bowery and Delancey in Manhattan). It even detected the closed 802.11b network at the Starbucks near where we're staying here in central California, and best of all, it can tell the difference between WiFi and a microwave oven (the lights on it go solid instead of flash). We haven't been able to determine whether it picks up 802.11g, since we haven't yet been in the presence of an 802.11g network (at least that we've known about), but since everything else works as claimed, we have no real reason to doubt that it'd do that as well. Why couldn't Kensington, supposedly a better-known and more reputable company than SmartID, get this right?