For what it is worth....
I had heard that the monster I have (620 dark) comes from the factory set up for a rider roughly in the 150lbs range. I am 6'2" and 200lbs plus gear. The bike felt very 'soft' and bounced alot even on semi-normal roads, nevermind the bumpier ones. At my first service I had the front springs and rear spring replaced. The difference was amazing, the bike felt much more firm and planted while riding and in the turns. I feel much more secure and safe on the bike now that it is set up for my weight.
I don't know if that will make a diff for you or not, but just passing along what worked for me and my bike.
best of luck.