Older PETs were limited in memory, therefor this one has a full 32K. The other limitation was the lack of CP/M which ran on most business machines. The used Basic (v4) on this PET had extra commands aimed for the business use of this machine. This also meant a lot of software came out aimed for the use in businesses.
One major bug was fixed in this release, the "killer bug" which could actually break the computer. It's also the first Commodore with swivel monitor and detachable keyboard.
Rumours go around that the design is made by Porsche Design. This is partly true. A design was made by Porsche, but it wasn't used. This design (possibly influenced by the original Porsche design) is made by Ira Velinsky.