My boobs are somewhere between 12G and 10H depending on the brand. So they're heavy, awkward, usually getting elbowed, and make far too much contact with cupboard doors accidentally.
They also sublux (partially dislocate) my ribs if left unrestrained for too long.
I had recently purchased a Shock Absorber Active D+ Classic that was Very Good but the bottom band has a tendency to roll up on itself after about 6hrs wear, and ends up tooth-flossing my ribs which is not ideal and quite painful.
I noticed the different closure for this model and figured it was worth trying to see if it behaved differently. It does!
The split closure spreads the load over a larger area, minimising the stress on the bottom band so the rolling/flossing occurs much less frequently and after longer period of wear. The only downside to this closure design is that if you're not flexible or hypermobile, you might need someone else's assistance to get all strapped in. Or maybe you've got smaller boobs and can wriggle in and out? I know I can't.
Both models of the Shock Absorber bras hold my breasts in against my chest firmly, I feel very supported and secure while wearing them. The straps sit nice and high on my shoulders, closer to my collarbone where the muscles can take the load. Excellent design, easily the best non-wired bras in my experience so far.