I was leaning toward doing them separately for a few of the reasons mentioned here. I definitely want to replace the fronts, but am not so sure about the rears, as I have never ridden in the back and it's hard to tell from the front how worn the rears are, as there is no exaggerated bouncing. Also, more goes into replacing the rears as the Burb has the Premium Smooth Ride Suspension, which has special, stiffer, auto-leveling shocks and weaker springs. I either have to spring (pun intended) for the Nivomat-compatible shocks at $250-350 each or replace the springs with stiffer units (effectively making it a standard suspension setup), making the full job $350ish total. I have no real need for the special suspension as I do not do any towing or heavy hauling, so it isn't worth the $150-350 premium to me.