How many Points of Interest (POIs) do you need?

location based services

Points of interest (POIs) are, just as the name implies, a geographic point that may be of interest to you. They are typically divided into categories like dining, shopping, lodging, recreation, etc. If you are navigating to a business, you are likely to use a POI; if you are navigating to a residence, you'll probably enter an address instead.
These days, most auto GPS receivers come with anywhere from 750,000 to 6 million or more POIs. I find units with 2 million or less POIs to be extremely frustrating to use, since often, the business I am searching for is not in the database.
I really like Garmin's approach to this. All of their newer auto units come pre-loaded with City Navigator, which has nearly 6 million POIs. TomTom fudges this a little bit, citing "miliions of POIs" for their products, though my take is that they are closer to the high end of the range than the low end.
Magellan and Mio put more POIs on their higher end devices. The Mio C220 has 3.5 million+ POIs, while the Mio C520 has over 6 million. Magellan's Maestro 3100 has an anemic 750,000 POIs, while the Maestro 4000 has 1.5 million. All other members of the Maestro family have 4.5 million POIs.
My advice? Avoid GPS receivers with low numbers of POIs.
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