The Porlex Hand Grinder has ceramic burrs and a stainless steel housing, which not only makes it easy to clean, but more resilient than glass versions, and produces less static than plastic versions. The conical ceramic burrs dont rust, are easy to clean and stay sharper for much longer than steel burrs.
The only real difference between the Mini and the Tall is size. The Mini is 130mm in height and fits nicely right into an AeroPress when the rubber grip is removed. The Tall stands at 185mm and has no rubber grip. The burrs in both grinders are the same.