Woodlands, 50 km. My handcrafted-in-Italy, titanium-railed Selle Italia Flite has seen better days. 49 months ago, thousands of km ago. While it is not torn, scratched nor cracked, it is wrinkled. As wrinked as a weather-beaten, aged face that has been sat on. It seems to sag a little in the middle, which is enough to give a pain in the butt after a few hours of cycling. So I shift it (the saddle, not the butt) 5 mm forward, so that the sit bones sit properly on the saddle again. This little distance seems to make a difference to comfort, but time (and over a hundred km day after consecutive day) will tell.
Yesterday, I went for physiotherapy. The therapist says my back ache has to do with the tightness in my hamstring and calf. He also says my right leg is clearly stronger than my left. Which might explain why my right leg got injured from marathon training and saddle sore is not equitably spread across the bum.