Well heres why i think it will suck,
1. Steam Powered.
2. Limited weaponry.
3. No CTF (That i know of)
4. No DM (That i know of)
5. The flight/gravity systems means probably no maps like we are use to. So i believe they have backed themselves into a corner if the only area all these gameplay elements work are in orbit jumping from rock to rock.
These are my reasons for why i won't buy it, until i hear otherwise.
Other than the maps I really don't see any issue. I'm fairly sure they still intend to update and aren't done with the game yet. I guess only time will tell in the end.