How can I transfer locations from old Magellan GPS to new Garmin ?

My Magellan Roadmate 360 was pretty impressive when new 11 years ago, but now is developing several "quirks" and I would like to replace it with a newer, faster, better Garmin. Over this time I have saved many locations that I have visited while at the location. (I do not have a specific address for most.) Is there some way that I can save and transfer these locations to the Garmin? Or do I have to visit each location again while the old Magellan is still alive and enter and save the location on the Garmin.?

Also, there are dozens (if not 100s) of Garmin Nuvi models available. Most everyone seems to agree that these are the best, but there are so many that seem so similar, how does one decide?

I am not interested in the most up to date unit, just something that will carry me through the next decade.