Is there a particular reason you want the 650t model? Buying it for the camera may prove to be problematic as you would have to remove it from the mount to take a picture.
If it's for the preloaded Topo maps, I think it would be better option to by the 600 model.
I have been using the 600 for 4 years and only had 1 problem (2 months ago). The touch screen was acting up and I had to send it in for a refurbished unit.
I use it my cars and have the Rugged mount on a RAM ball setup on both my bikes.
The touch screen works with my gloves, but sometimes you may press the wrong icon due to the glove fingertip being so wide.
I admit the Montana has more features than I need but some of them are really trick, like setting up shortcut icons to pick a pre-configured profile.
Using Basecamp for offline route and track creation does require a bit of a learning curve. I like the fact I can keep my routes in separate categories and only load what I need.
Creating a route on the unit is fairly easy. BTW, Basecamp is free to download.
I prefer to only load the map segments that I will use rather then the whole country as it speeds up some of the search functions.
Besides the Garmin City Navigator and Topo maps there are also third party maps (OSM) and device managers that can be used (I like JaVaWa).
Over all I been very pleased with the Montana. It's a decent compromise between size, features, and cost.