I replaced all four rod and spring assemblies and all four dampening straps. Access is a little bit tight to the rear rods but, other than that, the process went smoothly (after having watched a how-to video). In terms of my experience, I've never worked on washing machines but do most of my own appliance installation and repair.
At the beginning of the repair, I started second-guessing my decision to replace all of the rods (the rear ones are quite expensive and the first one that I removed seemed to still have plenty of strength in the spring), but by the end, I decided that it was probably the best decision. The tub was sitting higher and more level. Furthermore, I wasn't able to notice differences in strength of any of the springs on the rods I removed, so I wouldn't have been able to identify which ones to replace and which ones to leave.