I've been reading about these systems and it seems like some people like them on their cars and some don't. I'd like to get to the bottom of what these do and why turn them off. Feel free to correct me if I'm wrong with anything here.

ABS - Anti-lock breaking system
* When you slam your brakes, the ABS system pulsates the pressure on the brake pads so that they don't grip the brake discs hard enough to lock the tire. This prevents the tires from sliding and raises your traction while braking (because sliding tires have less traction).

TCS - Traction Control System
* When a tire looses traction, like when starting on an uneven dirt/grave/snow covered incline, the TCS system engages the ABS only on the tires that lost traction. Because of the way that open differentials work, most of the power from the engine goes into to tires with the least amount of traction. By applying the brakes to those tires, the power can be diverted to the ones that still have grip and can use it to pull you out.

VSC - Vehicle Stability Control
* When loosing traction while cornering, the VSC system selectively applies the brakes on some wheels in order to not over or under steer. This helps you maintain your cornering trajectory and prevents you from sliding off the road.

Some people seem to dislike these and I'd like to get to the bottom of why that is.
* Is the implementation of these systems simply broken on the 4th gen 4Runners?
* Do the systems wear down and go out of spec?
* Does switching to larger tires and not re-calibrating the speedometer (like most of us here I'd imagine) throw these systems off?

On-Road:
* Some people report that these systems kick in when they shouldn't, which could potentially be dangerous

Off-Road:
* TCS prevents you from doing donuts
* They prevent you from predicting what your car will do in tricky situations because you don't know for sure when they kick in and when they don't.
* Why do some people turn these off while offroading? Seems like TCS would help with climbing up uneven ramps that aren't steep enough to engage 4Lo or lock the center diff.

Any comment is appreciated. Do you like these, do you not and why? If you turn them off, why and when? Maybe also post a link with how you installed the kill switch.

Mods
* Enigma Engineering, turns VSC off (what about TCS and ABS? need to stop/start car to re-engage) 4th Gen 4Runner Traction Control Delete Switch Installation - Toggle Mod VSC Off 2003-2009 - YouTube
* rustbeltwrenchers, pretends to lock the center diff V8 4th Gen 4Runner How-To: VSC Off - YouTube, VSC Off, ATRAC On Mod complete! - Toyota 4Runner Forum - Largest 4Runner Forum