I'd say that leather is highly variable. I see it in other leather goods, I don't see a Brooks saddle as being much different. It is possible the tanning process has changed, I know that environmental regulations have impacted the industry. I have adjusted mine as needed. On my oldest Brooks, I've had to punch holes and lace it up. That corrected some sag and brought it back up to par. Mine oldest also dates to '05, but I can't claim as many miles. Still prefer it to other saddles, I purchased it for the durability, seems non-leather saddles only last a couple of years. I've had a pair of leather boots for 20 years, I expect as much from my saddle, with care.