it won't replace the slipper but will use some different parts - maybe different layshaft and I would assume it's compatible with both the slipper and standard non-slipper gear (but just a guess).
the centre one way is just like a normal 4wd buggy on-power, but off-power the front diff is free to spin and this helps the car rotate round the corners. I'm not sure I'll get one - spent enough
, but I'd not refuse one if it was thrown at me. I'd like to try it.