The Domination mode is more oriented to direct combat and more frantic. You'll never be far from a banner, which means you're always constantly on the move and in the center of the action.
In contrast to the Conquest mode, capturing flags Domination mode is much faster, and the rate of loss of tickets recurrence is much faster in Domination mode. Tickets also lose more slowly if your number of bases is minority. This means that each floor made of Domination means more to the outcome of the game in Conquest Mode.