The only difference is that the H4-3D was rebalanced to handle the H4. If you are getting one, might as well go for the H4-3D. Although, the H3-3D will work just as fine
Yep. But I just don't want to be the guinea pig :). Wasn't wrong when I waited before getting the P2 V2 than the earlier Flyaway Edition P2. Though I'm sure its going to be great with all the new features that DJI has added.
Try contacting DJI. If there is a service center near you, they'll fix it. From the problem you stated, theres definitely something wrong with your unit