I'll order the disable kit when I have money to do it (lower priority as Summer approaches too!).
Advantage? It all depends on your driving skills and preferences. That's all.
Skilled user control will always be better than jerky on/off automated control. If you control the torquey TDI while it transiently loses traction, but do not let off the pedal completely (like the TC does), you maintain momentum, and the wheels/tires regain control faster and smoother by virtue of fine driver input.
When you are on the edge of traction, smooth control, even with some slippage is far superior. The key is subtle foot movement, so that instead of jerky off/on action, you gently let up and regain traction smoothly. The torque of these TDI engines makes it much easier than a small gasoline powered engine.
Experienced, skilled snow/ice driver will continue to make progress while jerky off/on TC effects will cause loss of inertia. This is entirely a user choice. Full control is only useful if you know how to use the torque gently and constantly.
BUT, it is extremely annoying to have the TC turn off the engine transiently during hard acceleration-bad for the drive train too!!, jerky like crazy, and just plain dumb. Maybe I'll do it sooner, while it is still Summer! Even the OEM tires will be much better with TC disabled. Antilock brakes are much better than they were in the past, but a skilled driver can apply brakes more effectively in most situtations. For me, I am happy with the anitilock braking, because I do not respond to surprise obstacles in the roadway as well as I should. Accelerating is a completely different situation. I look forward to full control..