Soft Cups TTC

Ok ladies lay it out for me...instead soft cups. The good the bad the ugly. Who's used them, who's had success, how did you use them and how long did you use them. Is there a possibility that it would interfere with sperm meeting egg or harm my chances? Could I put it in wrong?! Lastly I want to use right after BD, are they had to insert after BD while laying in bed? Thank you and prayers.