First you need to determine exactly what you have. In Mapsource, click on the Waypoints tab. Do you see the same points listed along with their icons? Waypoints are completely separate from map data.
If you are certain that you sent these waypoints to your nuvi, then press Menu > Where To > Favorites and you should see a list containing the waypoints that are closest to your current location. Display of waypoints varies a lot on different nuvi models, but IIRC they should appear on the 205w although you might have to zoom in to something like .8 miles to see them. There are no menu options to either show or hide waypoints on that device... "it is what it is".
It's also possible that you have POI's instead of waypoints, and you could use POI Loader to send them to the Nuvi. It's possible that user installed POI's don't show on the Nuvi screen, not sure because this also varies a lot on different nuvi models.
I have had a Montana 600 for about a year and I love it. I no longer use my nuvi's in the car, I use the Montana there as well as on foot. It is a huge upgrade from a Nuvi 205w, although if you aren't used to the advanced features of Garmin handhelds it could take it little while to figure everything out.