Part of the traction control strategy involves restricting the amount of throttle opening the bike allows at a given lean angle. The way to the think of it, is say your traction control is in sport mode, you?re leant over and you roll the throttle fully open. The bike will not fully open the throttle butterflies, because you?re at lean. If you then repeat this in race mode, the throttle butterflies will open a bit more at the same lean angle. In slick mode (or slick traction control setting in user mode), this feature is reduced considerably.
Don?t worry about the term ?slick?, the standard ECU is very much catered for road bikes, so even if you run very minimal traction control, you?ve still got a decent amount of safety net in the back ground (on a dry day ?).
On a dry day, on road, with decent sport touring or general sport tyres, I used to enjoy Slick DTC -4 the most, as I found it gave a good feeling of connection between your throttle input and the rear wheel so to speak. @preynol1 and I did a test on a bit of road I know well ages ago and compared the difference between Race and Slick DTC in terms of driving out of corners, was apparently quite a difference