We got a 4 inch dunlop soft topper(20 ILD) for our PU base. We love it!
We have now ordered a 6 inch core of medium to replace that PU base. (The PU came from our former Tempurpedic memory foam mattress that collapsed on us in the rain forest where we live in Hawaii.) We discovered everything had body impressions, including the box base, which had sagged slats 6 inches apart with sunken cardboard over them and a cosmetic piece of some fabric on top. So much for Tempurpedic! We threw that out as well as the topper and slept on the floor on our new 4 inch latex and the PU base until we built a slat platform on 2x10 lumber--now we have a sturdy, solid, breathable foundation.
While we were on the floor we did notice a buildup of sweaty smelling condensation under where my husband sleeps in 3 days.
Now the mattress is breathing.
BUT...
How do we care for the latex so it will hold up?
My husband is heavy and sleeps hot.
Is it better to put a cotton topper on as well as the thin velour one we have?
Or just let his body vapor go straight through the velour into the latex?
I read on the forum not to put waterproof cover on.
But how do we keep the latex from getting ruined or smelly?
Or is it so wonderful that it just does not do that?
In case I am rambling too much, perhaps some of you latex verterans can tell us how to take care of this new investment so it will last 20 years!

Uh... pardon me if I say--GROSS! And having said that I suggest that you run, don't walk, to your nearest store and buy a mattress pad or maybe two. That way you'll have one ready to put on the bed while you are washing the soiled one. And hopefully you will do that frequently.