It sounds like you can only fly vertically, like a big jump. You also have to keep an eye on your fuel. When you decend, you have to fire it to slow yourself down. If you jumped too high with low fuel, you might not have enough fuel to land. Then of course landing will be difficult since anyone you didn't kill will be firing on the spot your landing. It will be pretty hard to land quickly while defending your self without hitting the ground too hard. And you'll probably be easier to take out since the pack is explosive.
It doesn't sound like it will be Tribes 2, this rocketpack is too limited. I can't wait to sneek up on a spawn point for them and shoot the enemy when they put that bomb on their back. I also hope it has splash damage.