I have only built the Monogram kit ( I think it was 1/48 ?)
But that was wayyy back in 1982. I built it as part of my grade in Aviation class ( I got a B so it must have been good ) I dont recall having any major issue's with it.
I gave my instructor the kit when I passed the class. Last time I saw it ( 2004 ) it was still on his desk.
I also had to fly a Helicopter simulator ..... but that's a totaly different story.....
( Can a Pilot fly a Helicopter 400 feet below sea level, and survive ...?)