CHP has to write pages and pages of traffic reports.
Sheriff = you can do almost every possible position in law enforcement; custody, court, patrol, swat, k9, air patrol, marine patrol, internal affair, transport, traffic/motorcycle patrol, etc etc etc.
Police = generally- patrol, traffic/motorcycle patrol, swat, k9, detective, and community services
CHP = CHP
Any large agency will get you seniority quickly.