CN vs OSM

I've heard here that having two maps active, especially two maps that are each routable, can cause problems.

I also have an 855 and I have at times had both City Navigator and a topo map active--or City Navigator and a National Forest Motor Vehicle Use Map active--and I've had no crashes* or anything.

From my testing with the above combinations on the 750, 855, and 2460, I'm pretty sure that different nuvi models handle two active maps differently:

-in some models, one map covers the other with no visual indication that the other is even there

-in some models, both maps can be seen (and this may confuse me trying to visually ID where I'm going)

There may also be some issues related to how the maps are made--maybe there's a map-making option of solid background and transparent background.

I've never used one of the routable OSM maps so don't know what you see, but having two active maps isn't something I'd routinely use. Maybe others can offer their experiences.

* I meant GPS freezes, but I will also state that my vehicle remains uncrumpled as well!

Please correct me if I am wrong.

I always thought OSM is better in Europe, but just adequate rest of the world. It lacks many information provided by CN. CN is not perfect, but OSM still few steps behind CN when filling the need.

Since I have lifetime map, I really don't consider other map in North America. However, if needed, I would use OSM while visiting other countries.

I only have an older version of CN maps on my C580, so I rely on OSM for most of my mapping (in NW USA). I make sure to only have OSM selected, otherwise, as you've noticed, CN (with its associated POI) seems to be preferred.

House numbers are only starting to trickle into OSM, and I haven't had much success looking them up, even where theoretically present, in the generated Garmin-compatible maps. Also, those maps don't apply common abbreviations, so instead of NE 25th Ave, you'd have to search for Northeast 25th Avenue.

As for coverage, that varies widely depending where you are. In the Portland, Oregon metro area, the local transit agency had a handful of interns work hard last year to reconcile OSM with detailed official government mapping, drastically improving the overall quality, and adding extensive cycling and pedestrian routes.

If I had lifetime maps, I'd probably use CN most of the time, but I'm cheap, and I like fixing issues on the map myself and being able to use those corrections within a few weeks.

Yes, it does have it's idiosyncrasies. One in particular is if you have only OSM selected, it sometimes is unable to calcalute a route/destination(don't remember the particular error), however, if you select the route/destination first, then de-select CN map, it works fine.

I used the OSM map for Costa Rica on my last trip down, built routes with it and added POI's. The map worked flawlessly throughout the country. I have downloaded maps for the US, but I have not tried to use them yet, but based on what I see in Mapsource, looks like it would be a non issue.