I had the Cybergun F2000 when they first came out. Basically it's a JG AUG aside from the externals and magwell.
18RPS is achievable on 11.1v, But the internals aren't up to spec or set up to keep up with that ROF reliably without shedding the piston/gears/trigger contacts.
Mine was pretty terrible out of the box. The barrel was shockingly bad. the Motor was frankly awful. I basically had to replace everything to get it even remotely decent. I eventually sold it in favour of the G&G F2000.
It's OK. The ETU is overengineered as a simple mosfet like all Ares built rifles (Yes it's an Ares), but gives you very little in terms of configurability. The Hop unit is pretty pants and needs modification to lift heavier bb's. At the moment I have only replaced the barrel and hop rubber. I will be at least replacing the Motor in mine soon as Ares Stock Motors are awful and is essentially being bullied into performing by the mosfet.
I do like my TM Aug High Cycle, However its almost unupgradable without replacing almost everything due to it's short stroked gears/high speed motor nature.
Disconnect the EBB mechanism before it breaks. The AA's System is just as bad. Both AA and G&G have proprietary pistons which like to crap themselves fairly easy.
Great externals, but I have had a couple of cut off levers break due to an inherently weak design whilst actuating the roughly cut sector cam, stock motor is terrible which I replaced. Interestingly enough the trigger unit works as a sort of mechanical mosfet.
You'll need to mod the selector so it will fire single shot, the dual trigger just does not work reliably enough to not get kicked out of semi only games.
It's terrible for your wallet. I own or have owned most airsoft bullpups so you don't have to. They all come with some inherent problems, usually proprietary parts which are pretty terrible, they all come with crap motors without exception and most have crap triggers. Ultimately you are welcome to purchase what you want, but you must have come here to acquire some knowledge.
What would I get if I were you? TM Aug HC on the expectation that I wouldn't mod it and would be happy with its performance despite the lack of FPS.
What would I get if I were you out of what you have picked? Either the F2000 or the Aug, they are essentially the same inside with the same issues, but not as bad as the L85. Beware of the F2000 mag compatibility. Mine was incredibly fussy even with Metal Stanag mags.