Out of the ones you listed, I would recommend the Flip or the Funtana. I dont even think the Razor looks like it would fly the way they claim it will fly. Also the Ucando generally comes out to heavy to get any decent performance with either of the engines that you listed. I haven personally flown the flip but it looks like more of a 3D trainer than the Funtana. In other words the Flip looks easier to fly. Another ARF that has gotten a few good reviews is the new H9 Twist. If you dont mind building a kit then either get the Morris Hobbies Sledge or any of the OMP profile kits. All are very good choices.