I need to respond to this to answer your question about the 500 to the general audience that might consider the bike for longer rides. It is a race bike and the design is optimized for that. The advantages are light weight, off-road racing toughness, superb handling and quick power. For example, the motor is designed with appropriate bearings to run without damage when upside down sliding down a hill next to you. The disadvantages are that you need to check nuts and bolts more often, check the valves once is a while (the new 500's head design is superb and valve clearance issues are things of the past) and probably change oil a bit more often. When bombing around the woods or racing I change oil between 4 and 6 hours of operation. When dual sport riding at a much easier pace in Utah I just ran the entire week and changed oil when I returned home. Since that DS riding was mostly off-road the oil was slightly dirty but I could have run another week. On a trip to Alaska I could probably get away with changing it every 2,000 miles. The 500 now holds 1.5 liters.
The other issue of comfort is subjective. I installed KTM's isolastic handlebar clamps (they definitely help) and have Woody's Wheel Works cushioned hub to reduce wear on the output shaft splines. With 50/50 or 80/20 tires vibration would be considerably reduced. You could also install the small footpeg rubber inserts that used to come on the 620 RXCs to reduce vibration there. And get a Seat Concepts broader seat for DS riding. The bike is very comfy. However, I grew up with Brit singles which had really nasty vibration, were unreliable in the extreme and had none of the 500s off road capabilities. My perspective on comfort is colored by this past experience.