Their charge is almost irresistible, and they can fight effectively in melee with their heavy cavalry swords, but they should not be thrown away against infantry squares. Even against other cavalry, they can give a very good account of themselves. They are, however, relatively slow moving and should not be used to pursue fleeing foes. The Empress Dragoons can fight on foot, if needed, using their carbines, but they are not particularly effective as an infantry unit.
Under Napoleon the Imperial Guard gradually became an almost separate army; it had infantry, artillery, and cavalry components, and even its own elite units within the already-elite Guard. By any standards, the Empress Dragoons, named to honour Josaphine de Beauharnais, were an elite force. All the officers were appointed personally by Napoleon, and the rankers had to have served at least 10 years in the saddle before they were allowed to join. Every chasseur and dragoon regiment of the line in the French army had its best non-commissioned officers taken. While this undoubtedly made sure the Empress Dragoons was composed of the best of the best, it almost certainly damaged the rest of the army by removing those same veterans from their original units.