Some users have had issues with the added weight, you can always fashion some means to add additional weight to the back of the camera if need be.
The benefits are reduced lens flare and improved contrast where a bright light source (most often sun) is close to being in frame.
Personally I like lens flare, if I can't avoid it I endeavour to make a feature out of it.
I run all my terestial lenses (with the exception of fish-eye) with the hoods fitted though, the contrast improvements are real. I don't have any hoods for the phantoms, principally because I expet it would be too fiddly and I don't like the idea of potentially having glitches in the video where the gimble is struggling to work with one fitted.