you just answered your own question, good boy!

see 1000's are faster than 600's, so at the end of the straight your carrying more SPEED, with out fairings or a windscreen there is nothing to block the wind, i won't go any deeper into it as to not lose you, but if you want to find out more look up the terms aerodynamics, horsepower, velocity, and common sense

on the south straight of the full course i was flirting with the limiter in 6th depending on my drive off of oak tree, i could have easily bounced off the limiter, i just wouldn't have made the turn, if i was a better/braver rider or the bike had a little more power though i'm sure its possible... i was hitting and holding a indicated 186(as high as the speedo will go, but a bit off i know), guys on 600's i spoke to were hitting 150's, thats alot more than 15mph difference, and also when they do get close to that aerodynamic barrier they only have 90 some hp pushing them and probably weigh alot more than me, i'm skinny and have almost 170 hp working against me, in otherwords, hard to hold on to... damn sorry i didn't mean to get that deep and technical on you, my apologies if your sitting there scratching your head in confusion

and its not about being scared, its about not wanting to throw a $2,000 set of plastic into the tarmac, i would think going to a trackday thinking theres no chance of you going down is a far worse thing because your either over confident or going to be tip toeing around getting in the fast guys way