I had a Nuvi 1350 for awhile and just can't agree with you here. I suppose it depends on what kind of maps you are using. Or maybe they fixed some things in the firmware after I gave mine to my daughter? The most glaring error was that polygon 0x51 (wetland/swamp) was rendered as water. I live in a coastal area where there are large wetlands - these are often just low areas that are seasonally wet and not "lakes".
Here's a comparison I did in 2009 between the Nuvi 5000 and Nuvi 1350 using Garmin's Topo US 2008 maps. The Nuvi 5000 correctly shows the river that passes through the wetlands. The Nuvi 1350 makes the whole area look like some kind of huge lake. Also note how fat the contour lines look on the 1350. They are wider than the minor roads. I think this is a mess personally, but maybe it's just me.


Now here's an example of a topo map I made myself. I was able to get around the problem with the wetlands and elevation contours by defining them as custom bitmapped types. Garmin doesn't do that with their ownUS maps though, and very few (if any) of the map authors here do that either. But notice how the 1350 fails to show the place names (Buckshutem, Port Elizabeth, Ormond, Muskee Hill, Jonesmill, Bricksboro, etc).
My own experience is that the older Nuvi models - like the Nuvi 5000 in these screenshots, or the 2x5 series - do a much better job with topo maps.
