A true 3 link can be very difficult to tune , I believe what you are talking about has far less adjustment possibilities but you still need adjustable shocks to dial in the reaction of the car / traction , I don't see a 4 link as the hot tip for cornering either , you will need a panhard bar or diagonal bar to keep the suspension square as well where th eleaf spring provides both lateral support & a small amout of rear steering , as the leaf spring flattens on the outside the diff is pushed back slightly , no 4 link can do that .
