I ordered a size up but the waistband was still way too small. The wider waistband did make them more comfortable than most tights. Tights are soft and good quality but waistband is appropriate for smaller size than what I ordered.
These tights are absolutely seamless, even on the convertible feet. Waistband is really wide so doesn't unflatteringly dig into your waist. Run small. Most durable of the seamless tights I have tried.