Oh, there are lots of citations!
In the meantime, after several changes between both belts, I guess I have a quite good experience.
Waist style is more restrictive, since it restricts certain torso movements more than hip style. It is true, that the shield tightens more when spreading legs compared to hip style. But in this respect, the difference is not too big.
For me, hip style is as secure as waist style. No chance for me to orgasm while wearing both belts up to now. However putting or pulling something below the shield is easier with my hip style belt.
Vanessa is right, hip style shows less under clothes. With high waist pants, short tops are wearable.
All in all I like much more hip style, because it allows more movements and more clothes. Only the shield of my waist style cb is better, because it is not adjustable, so the there is no additional lock, which makes the shield very flat. I am thinking about to get a similar shied for my hip style.
However, what I can recommend to you the most, is to change between both styles frequently. For me, it is a little more comfort, if the pressure spots change from time to time.