Do you (explicitly) use zram or zswap? With zram I primarily mean using it as a swap device, but would be nice to learn other usages for it too (I know that another common usage is for /tmp).
Archwiki says that since kernel 5.7 zswap is enabled by default. Does it matter for those who are using zram already as their only swap?

I have used zswap with systemd-swap in the past. It worked well.

If zram is working for you, I would just stick with it.

It does seem to work well, I currently use it for swap (zstd) and /tmp (btrfs/lz4). But zswap would allow hibernation while providing similar benefits (If I understand it right). I never used it before though.