I love bullhide, it is one of my all time favourite leathers to work with. It's heavy, but flexible, and comes in a range of wonderful colours. It makes superb floggers, as you'll see elsewhere on this site, and it also makes for pretty wonderful restraints, too.
The thick, lush quality of bullhide provides excellent padding for these restraints. The main points of stress in restraint use are first in the strap, which is resisting the pull away, and second in the wrist/ankle, which is bearing the brunt of the pull back.
We use strong firm strap leather for the former, but that's not entirely appropriate for your delicate body parts. That's where the bullhide comes in. It's strong enough to cushion the stress against your joints, and soft enough to do so comfortably.
In addition to being tough, solid restraints, they also happen to look (and feel), stunning.