There was a tech bulletin released recently - LTB00448v5 (v5 for version 5) for hesitation and engine flare on gear change. It involves a software update to the PCM (Powertrain Control Module). I have just had it done and it makes a big improvement to low speed drivability especially first to second gear changes. It is for Defenders in chassis # range ca423911 - da431347, which apparently covers most 2012 and 2013 vehicles.

