I ordered two copter x kits from bg and setup both with cc3d atom and they are flying nicely. One has a tail motor and one is belt driven with the align dfc head and swash. Both using lemon sat powered from a tiny converter 5vdc to 3dcv. Both have carbon fiber blades as the stock plastics are trash.
The one got the tail motor after the belt was twisted inside the boom and twisted til it pull the slider to one side. Heli went in to a spin and tipped over and bent the metal boom. Twisted faith because I wanted to try a tail motor in one and install a cf boom. That worked out well. The tail motor version feels like a smaller 230s.
Had a tough time setting 0 pitch because the plastic blades were warped. Got it real close and left it, when the cf blades went on it is almost perfect. The plastic blades also made an awful sound when unloading. Very annoying. Also the plastic blade made everything hot for five plus minutes using a 1000mah25c. With the cf blades, things are much cooler and I get nine plus minutes with the alarm set to 3.6.
Two different brushless motors, so performance is not the same. I can do any setup on the tx as I would with other cp helis. And still using the mixer settings dished out by LibrePilot. Both are very stable and responds very well. Had thoughts of all the negative I've read and I'm a bit surprised. I wanted to use the copter x as a start to do my masters, but I love how the 250s turned out and I like the air frame better so the masters remain.
Just some photos and a dark indoor video. At the end I got distracted and put it into a heli box. The cf blades sliced right through it, luckily it wasn't me. No damage as one linkage popped off. Negligence on my part there. I hate hovering sometimes - just want to turn it loose and fly. I can't get over how smooth it feels.
https://www.rcgroups.com/forums/showthread.php?2893778-Copter-X-250-With-CC3D-FCRic...