If you mean I can now leave the esp/tracking off when 'racing' someone, yes
otherwise I leave it on
I was actually thinking more high-level, from a design perspective.
Generally, a Limited Slip Differential is used to ensure that power is distributed across the driving wheels through the differential even when one of the driving wheels is on a slippery surface where without an LSD that wheel would free wheel and power would flow there rather than to the driving wheel. With ESP traction control, when a wheel begins to slip, the car applies the braking system to that wheel, pushing power to its mate on the opposite side of the differential thus performing the same function.
The difference is that the ESP system costs some power and braking performance where an LSD operates typically via some type of clutching mechanism in the differential, which doesn't affect the braking system at all and absorbs a minimum of power. So an ESP system can effectively be used in place of a LSD and probably costs a lot less.
(My old Land Rover Freelander did something similar to ESP but for rough terrain crossings: you enabled the "descent mode" traction control system, took your feet off the brake and throttle, and it balanced the operation of braking system and throttle control to successfully negotiate incredible inclines at low speed, maximizing tire traction without having to go out and lock up hubs or switch a transmission transfer box into a fore/aft or side-to-side locked 4WD configuration.)
'Full-locker' differentials are often used on dirt track race cars to ensure that the driver can break traction and slide through corners, but allowing the wheels to rotate at different speeds on drying surfaces when otherwise they might break pieces in the drivetrain. LSDs with lower torque transfer percentages are generally used for road cars to enhance traction on varying surfaces, based on the amount of power that the car has and the intended about of drift and wheelspin that the designer feels optimizes handling characteristics. ESP systems are significantly less expensive and much more adjustable to work with, considering the downsides of braking performance and power consumption they imply.
I like to study and consider the engineering bases of these things ...
But now I think I'm going to get into the SLK and go for a drive. :-)
... A time for study and a time to drive ...