By "receiver only", we are referring only to the communications capability of the device.
Depends on what the TS meant by "to track someone" but I am quite sure he did not mean keeping a log of the track, which is what not only Holux but some Nuvi models and GMXT can do. What I am sure he is referring to, and what we are discussing, is the ability to track (as in to follow the movement) of someone remotely.
Even if checking the tracklog is considered one way of tracking, it will be very unreliable. It would require the person tracked to be a car driver, the device to be "on" all the time, which is unlikely to be the case if the device is "on" only when in the car, and the driver may not always turn it on, particularly if he is on a clandestine trip. There is almost always a limit to the tracklog data, after which it is overwritten. And at the end of the day, you still need to gain access to the device to retrieve the data.
And for many types of situations where there is a need to track someone e.g. parent tracking child in case of kidnap, owner tracking movement of container in case hijacked, this solution will not work. Coz if the child or vehicle detours, you will never know coz you will never get your device back.
A tracking solution such as the one I discussed about makes use of a device e.g. mobile phone, that is always on. The device will still be on when the person leaves the car, or takes the bus or mrt. The person may not even be aware that there is a Latitude app that is running.
A parent, wife or employer can monitor the movement of the person real time remotely via computer or mobilephone. So if your son says he is going National Library to study, but on your computer you see his phone moving to Orchard Road, then East Coast Beach before going back to National Library for you to pick up, you know what to do.