51 year old too I am using my Varg Vet Tracks and single track and I live in Utah.
-Bike spring for my weight.
-Revalved suspension made a big difference I can adjust clickers for trail and moto cross. Midvalve was to harsh on stock suspension and I feel like the frame is to stiff.
-I have a set of wheels for trail and moto
-Trail range for me 30/35 miles 20/30hp. Regen from my experience does not charge the battery enough to count on it.
-Fun bike but when they break it sucks. 3 months to get my back. Motor and battery went bad at 80hrs.
-I love the Varg app for the iPhone. I keep the Varg phone in the garage.
Side note my 17 year old son is close to my weight he is a pretty good B rider motocross. With current suspension setup he can rip the Varg on the big boy tracks.