4-500 miles?
I guess that would depend on how you have the bike setup. The adjustable suspension would help you alot, that is set it up soft and roll! The M2 Cyclone doesn't have a fairing, so you would have to figure out how much wind you can stand. It also has more of an upright seating position.
My farthest trip on my '91 was to the dirttrack races one time. 350 miles there, sat in the grandstands all day, 350 miles home. Other than my ass feeling like it was tattooed to the seat, I was OK. It was hurting. That bike has a good fairing and more of a laydown riding position, so the wind blast didn't fatigue me as much as it could have.
My farthest trip on the '96 was about 300 miles one day. It has higher bars and lower pegs than the other bike, so it was a snap.
The '91 gets better mileage.