We took a recent long drive and stopped at several superchargers. At one supercharger there was a Toyota parked next to us. No problem using the supercharger.
Older Teslas, like mine, are usually charged to 80%, with an occasional charge to a higher amount when travelling (we charge to 100% at home if we are taking a long road trip, but may charge to 90% at a supercharger). Newer teslas, with newer batteries, can (and I think maybe should) be charged to 100%.