The stock leaf spring Mopar setup is very capable. Most open wheel dirt circle track cars use Mopar type leaf spring in their GM based chassis' that originally came with a 4 link coil spring setup.
Mary Pozzi in a Pro Turing Camaro has won and beat out many super trick 4 and 3 link setup in Goodguys autocross events. Granted the driver makes a big difference and she is a national caliber SCCA Solo II driver.
A well thought out linked rear has the last little big of refinement and precision that a leaf spring lacks. You will not use that bit of refinement on the street. That refinement is going to be felt and ultilized on the track and by an experianced driver.
Now if you are going for a "look" and need air bags to do that, a linked rear and coil over front is sort of a requirement.