being able to move units from one end of the board to the other in 2 turns.
Yeah but only 1 unit. That's 100 points for every unit you want to move 36" (it can't shoot or assault when it exits). If you wanted to transport more it would take 4 turns just to get back where you came from as you can only turn 90 degrees each turn. It takes 3 turns just to turn around, then it would take another 3 turns to get across the board again.
More than likely you would have gotten shot down before this or ended up off the board.
If you think of going off board to enter ongoing reserves:
If you roll a 3+ and enter on turn 2, zoom 36", drop of a model. Trun 2 get off the board, turn 3 enter the board again a going back to your deployment, turn 4 pick up a unit, 5 off the board, 6 turbo boost across the board.
Picking up a non dedicated unit on your side of the board (turn 2 if you got it in) and then dropping it off next turn (3), after this there is basically no chance to pick up more units unless they were basically in your opponents zone already (which could pretty much only happen through outflank or deepstrike).
You can deepstrike with all jump infantry, jetbikes could just turbo boost the same distance. So which unit would be overpowered to do this with? Flayed Ones? They can Infiltrate or Outflank as it is.
Deploying a unit of Overlords or Crypteks is pretty much the only thing that could even be considered OP as it's the only unit that can't already get to the other side fast. Then again you can put them in a Ghost Ark and just drive them there by turn 2 anyway now that I think about it...