I was scared to hell when I rode my first one, but I did it anyway while just thinking of it as a bigger, more dangerous bicycle. lol
Been riding one (for leisure, not main transportation) for 6 years and so far, the only time I dropped it was when I was turning in an intersection near my house. Someone had spilled loose gravel in the middle of the intersection and as soon as I hit it, it was basically like hitting ice. I didn't really get hurt as I was only going about 20 and managed to jump off as it was going down. Scary as ***but that was about it. Only thing that happened to my bike was the left-side mirror got bent and a few scratches on the fenders.
I usually don't take mine over 70 and that's in the rare chance I'm on the interstate. If I'm on a normal highway (55 speed limit), I'll usually go about 45-50. Gives me plenty of reaction time as long as I don't follow any closer than four car lengths.