I'm using Bridgestones S20's and I agree they are awful on the S1000 especially in wet.
Vague at the front, well no demo bikes handling is going to be any good, unless the dealer spends 10 minutes with you before you go out and sets up the suspension. But even after that I will say the front shocks aren't very good and need a new cartridge kit or at very least, respring, revalve and heavy oil to help damping.
Quickshift should really only be used in higher revs, but mine took awhile to "bed" in and become easy to use.
Not trying to persuade you this bike is the dogs gollies because it does have its faults.