It is all personal preference, there is really no "best". If you bring the Drone DX into this also, then I would recommend the etha, IMO only though, I have no clue what you want. I just really like the etha overall, I just dont like the feel in the hands of any of the macdev markers. My personal rank would be;
The drone will be the smoothest, The Etha the most reliable and comfiest in the hands, G5 will be something (havent heard much about them yet)
the drone and the etha in the end have the same basic internal idea, a blow forward spool bolt type design.
Vicious CSL #3 --- Candy red ninja 68/45 --- SEED Rotor
Etha --------------------Ninja 68/45----------- Rotor