Just wanted to know some experienced opinions on improving my tired suspension. I have an '85 xr600r. My questions are: 1. Should I have my rear shock rebuilt or buy a Progressive Suspension 420 series shock? 2. Cartridge emulators vs. Progressive Suspension's dampening rods and progressive springs or "straight rate springs"? I ride everything, but mostly ride desert trails at speeds avg. between 25-55mph, not a lot of tight stuff.