I am a Garmin owner - have quite a few different models as I run them in my truck, )Nuvi775t) on my boat(GPS Map378), on my dogs(Astro320 & DC30 collars), and me (Rino 530 chx).
IMO - neither - pay a bit more and buy one you can upload Topo maps using a computer and/or accepts data chips such as the Micro SD card. That way memory is no big deal. You will never regret it.
The Rino 530 chx ( might not be produced but they have newer models) has GPS Map and a 5Watt radio. I can get Norad weather where I am instantly. If you have two of them it shows the other guy where he is on the GPS Map.
I went the route of trying to save a buck and have some models with built in memory. Never again.
JW