I have the same RockShox specced Spire in medium. Only had 2 weeks, but ridden almost every day, including bike park shuttles. I also found rear end harsh at recommended sag. But solved it by adding tokens and reducing pressure. Stock was 3T, gone up to 4.5T (which is max). Also got a coil coming soon... which was always my plan. Everything else in the review I totally agree with!