Nolo comprehendere. You're trying to compare 'BF'- Battlefield Evo?- Mongoose's ground combat game, with Ground Zero's space combat game, on the forum for Mongoose's space combat game? Does not compute.
On the only assumption that makes sense on this board, Full Thrust vs. ACtA, people who grumble about Mongoose's excessively rapid updates take note; there are bits on the GZG website that have been there for playtesting for five years...
I personally like the FT system. It shows signs of vegetation, though; designed for simple, fast play, got overgrown with complex bits like an ordnance phase. The optional vector system is about as intuitive as vector movement will ever get.
FT's basic mechanics are also more flexible. Systems really can function differently one from another, alien tech works alienishly. Which can be a mixed blessing. There is also a construction system that produces more or less approximate balance and can duplicate existing ships- typos permitting.
The big problem Full Thrust has is some of those alien and perpetual-playtest systems. Balance dubious verging on absurdly broken. Heavy Missiles, Kra'Vak railguns, Phalon plasma bolt launchers and pulsars, Japanese space navy hyperspatial distortion weapons, Futtock Guns (Nova Cannon)- all cheese. Beardy cheese.
Also, no flavour. No existing background to tap into, their background is interesting but low- key, colonial warfare in space. Too many tacky jokes, as well.