I've got just a hair under 40k miles on my '07 650R. My longest trip so far is 3000 miles in about 4 days. I have a decent ammount of mods to it though.
No windshield (try it before you knock it)
Airhawk seat cushion
GPS mount and 12V cigarette plug
I recently put my name into the hat for a Russell day long sport seat and I should be getting my seahorse 720 cases real soon.
The only thing left now is the suspension, which needs work in a bad way.
Are there better bikes out there? Of course. But for me the light weight, good mileage and cheap cost make this an almost perfect bike. Plus it's cool to be different. I mean, who tours on a Ninja?