the benefit of the chronos is that it allows you to use 'poor mans front diff lock'
once in 4L with rear difflock engaged, (rear diff ON disables ABS), you can toggle the chronos to 'Traction on'
This bypasses the ecu setting to re-enable ABS / Traction when it senses slip.. so ineffect allows you to have both front wheels simulating diff lock, by the brake being applied to the slipping wheel.
Rear with diff functions as normal.
I've personally found the above to be excellent when stuck in a criss-cross crest with 1 front and 1 rear wheel in air with no traction. was able to use front (with chronos simul lock) and back wheels (with diff lock) to get out of the situation without a tug or digging.
Kill switch works fine and does the same as the chronos.. unless you want the simul front locker.
(I have the 3.8 with chronos installed.)