The only flame here is directed towards trolls, not newbies.
In my opinion, G&G, KWA and CA are generally equal to each other. They each have different strong and weak areas, so it keep any of them from really jumping into a clear lead against the other two. You hear horror stories about lemons for all three. Conversely, they all have their die-hard fans. I really don't consider one more newbie friendly than the other two.
Since they're all derived from Marui's design, they all accept more or less the same aftermarket parts. Tolerances/fit with exterior aftermarket parts may vary, but that's hard to predict without reading through an insane amount of reviews and problem threads.