Real sword has in fact made some pretty cool guns. As far as Airsoft goes, usually wait a few years before buying any "new" system. There will always be bugs.
A Systema PTW is the absolute closest to feel and weight to the real thing. My military friends are always impressed by it's structure. Being that it's an electric system though it has absolutlely no kick when fired. The GBBR however, does. Not realistic kick or sound, but enough to make it interesting.
PTWs require different care and maintenance than other guns. If you want to know tge utmost about them, read any posts on ASC by MacGuyver, and any international threads by Tackleberry out of the UK.
The PTW has one major downfall, and that is the motor. It's design is remarkable, and is makes AEG motors look like toys. The problem comes with the manufacturing. The motors are prone to developing dead spots due to their armatures being wound too tightly. This means your motor may last for four years, or four months. You can have them hand wound by Tackleberry if this happens which will add years of life to them. But it isn't cheap to do, as you must ship them to the UK. It is however, totally worth it.
Understand that PTW accessories such as magazines, cylinders, etc are also expensive compared to many other guns. Once again, it's worth it but you'll pay. Fifty a magazine and near two hundred for a cylinder.
As for FCC, we haven't personally put those parts through their paces ourselves. I've heard mostly good things so far, as they have some interesting ideas. Their motors have mixed reviews. But you may find more in depth reviews from the US right now about them.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē