Speaking as an ork player, da jump can be awesome first turn for sure, if it goes off and if we make our 9" charge. It looks great on paper to use every turn, but in reality, during the second turn we are either already in your face and don't need to teleport in any other units or our opponent has wisely targeted any potential da jump recipients and we don't have a 30 boy unit candidate to move.
As wyddr stated screening can essentially make using da jump very lack luster. Many games are won or lost during deployment and a wise tactician can effectively nullify or nerf any teleport/deepstrike shenanigans with a good deployment strategy, as long as they bring sufficient screening units, which are really essential in any competitive games with todays meta.