Here is some info from Dylan that you might find interesting:
Dunlop just released a new sportbike tire, the Q4. This tire is different from what many think it is. It is NOT an improved Q3+ but rather a whole new category of tire. Its purpose is to provide a street legal tire with excellent grip, no need for warmers, that is at home on the track or on your favorite twisty road. Essentially it fills the gap between the Q3+ and the street legal race tire, the GPA Pro.
So the progression looks like this:
Q3+. Best all purpose tire. Harder center band for commuting, with sides well suited for cornering.
Q4. Best for trackdays and canyons/twisty roads. Warms fast, less sensitive to pressure settings. Single compound across entire tread. Any loss in overall mileage is gained in grip compared to Q3+.
GPA Pro. Essentially a race slick with grooves. Warmers strongly recommended particularly when cool and pressures checked and set before riding. Street legal. Poor choice for commuting but good for twisty roads and very much at home on the track.
Slicks. Pure track only tire. Warmers strongly recommended with pressures checked and set before riding.