Anyone had experience with longevity of latex? Will a latex mattress really not need to be replaced for 20 years?
Hi withinadream,
Welcome to the Mattress Forum! 
There is a good post that covers quite a bit of information about latex durability in post #2 here. Some of the posts linked there can get quite detailed.
In general, I consider anything over ten years to be “bonus time” for a good mattress. There certainly are stories of people keeping their latex mattresses for decades (see the links in that post for people using latex for over 50 years), but it’s not something I generally recommend nor consider normal. 20 years wouldn’t be abnormal at all for a good all-latex mattress, but I wouldn’t select any mattress expecting it to last 20 years.
Phoenix