Once a reservation what I am developer but not user! The first I find route by myself and then make routes for user with Garmin maps and device. For first task I use any soft and device not excluding the very big wheels on auto and legs, hands and belly on me. So I know way and only then see it on Garmin maps in my Karelia and nearest regions.

It all depends on the location but in main.
1) Navicom have more detailed map. Navteq have less detailed but more accurate. There are not all unpaved roads on the Navteq but on existing roads the route is more accurate. I often lose route on the Navicom but there are no recalculating on the Navteq in same place.
2) The address search on the Navteq is more perfect than Navicom. In Petrozavodsk the Navteq find almost 100 percent of address but Navicom find only half of its. Even fuel stations is named on the Navteq what is very important for Russian fuel quality choice.
3) In opposite your mention the Navteq is very well balanced with respect to minor roads. Navicom absolutely does not have notion about that outside of Moscow. It is normal for Russia!

In any case all Russian maps of NorthWest is very weak. I know the hundreds of places what is not correspond to reality with a very long time. So it is very good to combine any available map sources.