both are great in its own way:
I have the old don and a couple of empires. Im not sure on the new don's finish but the new head is a big improvement for tank oriented mods.
Old Don:
able to swap out the connectors for 510/901/801, optional or add on your own adapters for whatever connections
remove center piece , mini
vaping (16340,18350)
adjustable throw firing pin for different lengths of batteries
master on/off on the button
optional laser engraving
Empire :
901 connector only, but comes with 510 adapter, or you can put other adapters for whatever connections.
telescopic center, no center piece to remove since its one piece easier to adjust to whatever battery you use vs don's adjustable throw, you need a screwdriver.
empire comes in many colors, optional purchase for mainbody sleeves, the finish has a better quality than the don.
master on/off ring on the button
stand for your empire
both are all mechanical
don is cheaper in cost than the empire, but the quality on the empire outshines the don imho.
what won me over with empires:
no tool needed to adjust for different lengths of batteries
quality of finish on the empire
many colors to choose for the empire
I have 3 empires and 1 don... but at the end of the day, go with what you want... both are good mods in its own way.