Both my belts are thong style.
My mom did not accept chain style since she suspects it to be not secure. Additionally, I fear that chains are pressing into skin when sitting and that it shows under tighter pants.
Rigid style was refused by me, because I suppose it to be too annoying and too restrictive. And I cannot imagine, that rigid style can be cleaned on the back side while wearing.
In my opinion, thong style (or cable stye) shows the least under clothing and I guess it interferes the least with daily life, because it is just hidden between your cheeks. In the beginning, it was annoying, because it presses on the tailbone with certain movements, but I got used to it. Defecation is possible by pulling the cable a little to the side. Cleaning on the back while wearing it is easy, because it covers just a very small area. The cable can be cleaned just by wrapping a wet wipe around it.
I can only speak for thong style, but I think it is the least evil.