I experimented with this download (two months after I got it) and came up with some interesting stuff when I used MapInstall and transferred the full map to the following units: Garmin Mobile XT (5.00.20w), a nüvi 200W, and a nüvi 1300LM.

1. The map seems to work properly in Garmin Mobile XT. Tapping on the POI search button allows access to Man-made Places, Water Features, and Land Features, and allows navigation to those features without issue. However, the segment limitation on Garmin products requires combining the map segments into larger chunks for use on Garmin Mobile XT, similar to the procedure used for combining topographic maps.
2. The map does seem to display in reasonably current units such as the 200W and 1300LM. However, it is impossible to route with either unit and none of the built-in POIs (man-made places, water features, and land features) are accessible. This may have to do with the segment limit, since the full map is over 3,000 segments.
3. This is obvious, but the roads have changed dramatically between 1999 and now. Yet as promised, this is a fantastic resource. The only minor drawback is that it requires MapSource. Basecamp cannot see the map.