The 7, which is a racebike from a decade ago, was built longer & lower than today's sportbikes. It was built to be supremely stable & strong, with the tradeoff being more weight.
The 6 has a shorter wheelbase, less weight, and is built to ridden like a racebike with the riders' weight placed far forward. The seat height accentuates this.
I was surprised to see that the seat height of the 6 was a good bit higher than that of my 12.
Get whichever bike you're more comfortable with. The difference in skill between you & whoever happens to be riding next to you at the moment is going to be much greater than the performance difference between the 2 bikes....