I think STOs are just another name for an ICO and are nothing special. The most important thing is to research any project before investing. Saying that, this project looks very interesting and they have raised a substantial amount through their current fundraising phase.
The BaFin (German SEC) has approved their product and the BaFin has very strict regulations. Before Bitbond some other ICOs started in Germany and most of them were not regulated and scams like Savedroid or Envion. The regulation by the BaFin is no guarantee for success but they won't pass something with their agreement where they aren't sure about a good quality and save people from financial risks.