Druss,
I agree with you on the battery that comes with the kits apex if I recall.As far as the 401 gyro goes I’ve seen no difference so far between its performance in my 550 and the 600. It holds the tail like its in a vise. I dont think Id use it in a nitro 600 or larger due to greater vibration but so far ( a few dozen flights on the trex 600 ) it seems to be working well. I’m also not doing very aggressive flying, just sport flying. If I where going to do anything more I think I would upgrade it as well.
Same goes for the zippy batteries I’ve been using , If I where doing anything more than sport flying they would have to be upgraded.
I guess the point I’m making is that someone could put together a 600 size Heli that would be suitable for a beginner for somewhat less than 1500 and still have a safe Heli. Then as ones ambition, flight skills , and budget increase the Heli can be upgraded into a complete 3D monster with all the trimmings.