Unlike the majority of pure s&v'ers, you could take away his volleys and he still had a very capable ground game. Arguably, the greatest ohbh in history IMO, although Gustavo Kuerten is DAMN close. Although he had that weird looking forehand, it was still VERY good and could control points from the baseline. OTOH, take like a Martina Navratilova, and strip her of her volleys, and I bet she's a 5.5 player. Nothing against the great Martina, I'd commit treason to volley like her, but...
Edberg (and Mac) are the embodiment of LEGS. Both had quadriceps of a speed skater in their day. Sometimes when I see Stefan execute a stop volley that looks like the ball landed in dry sand, I wonder how someone could be so good.