I use LVM and have enough storage that all SSD would be a little expensive so for the last few years I've been using the block caching LVM feature with mirrored NVME drives as a writeback cache to my large HDD array. It greatly increases the performance of the storage with little hassle.

If haven't played with gluster for a few years but it has a tiered storage feature so the most recently used files actually get moved onto the high speed storage medium, which depending on your workloads might be even better, assuming gluster is now performent and stable enough.