I m using a 120mm, and I know it can pull over 7 kg, but simply the batteries I have right now are too weak (quite used and not that powerful to begin with).
A thrust to weight ratio of 0.8~1.0 is overkill: the habu 32 can fly comfortably at 0.5 thrust to ratio. Of course it's not ballistic, but it can take off well enough and can cruise around at 1/3 throttle.
I do agree with you on not rushing it though, I think I will maiden with new batteries then decide if I should use the weak ones as well or not bother.

Thanks.<br type="_moz" />