My personal favorite is the Harlan 2018.
I switched to Mazuri 6f a few months ago and almost immediately noticed a change in production and water consumption (also urination obviously) so the smell was worse.
Harlan is #1 in my book. I would rather have it shipped to me and get less out of a bag than the Mazuri because of what I have witnessed myself already. (less out of a bag=less pounds as 2018 is 33lb and 6f is 50lb).
I'm waiting on my next couple of bags of 2018 to come in now...hopefully monday!
I have never heard of the Sand Valley. Where do you get it?