The chip dissipates the heat via the ground pins, center 3 pins on each side. A heat sink is a good idea for currents over 1.0a.

Picture is of an old 486 heatsink, in open air running at 2.5a it gets quite hot and so a cooling fan could be used additionally.


I think its going to come down to the users individual preference, i myself like to keep things COOOOL !