That movement in the tail slider guide is the same in the RS4. On mine the bearing in the guide was not 100% smooth which caused the guide pin to rattle in there so I had to replace it. Would prefer a more traditional ball type guide that doesn't have so much play in it.
The design looks very similar to XL V2 (which is a great heli), especially the main frame upper half, main rotor included. Everything fits perfectly with no play at all. Tail boom is fixed by too bolts laterally, what seemed insufficient to me. So, I decided to place a screw crosswise to the boom to make sure it will not slide in, just in case. This heli flies really good. I can do maneuvers easier and in a more precise way than with other helis I have. However, this project is not a breakthrough. You surely will find helis as good as this one in the market nowadays.
I don't get why folks think there's levels of building in today's helis. There's 2 ways to build these. Build it or don't. They are all plug n play. Follow the steps and screw the screws in. Anyone can build these
