Garmin Oregon 450t vs Oregon 550t vs Montana 650t in GPS technology and devices Posted May 11, 2012 I have the Montana 650t and love the large screen. The readability of the screen sold it for me over the Oregon. Now, I use the 650t for everything, geocaching, driving (nuvi mode), boating, and hiking. The 4 inch screen is very clear in sunlight and the backlight is bright in the shade/night. I suggest you go and hold both in your hand to really compare on size and weight. Bottom line for me, the Montana allows me to easily read the geocache descriptions, logs and hints. Its also easier to input text on the larger screen.