I've been enjoying this renewed focus on memory efficiency. On my personal system, I've noticed that even with loads of memory, having a large swap partition really helps out when a big burst of memory demand comes up, like then running a large compile job. And that even hours or days after the memory demand is over, I still have gigabytes of memory sitting in the swap page—evidently the programs don't actually need to use that memory at all!
I'm really looking forward to deviceless zswap as an easy "compress my ram" option that plays nicely with cgroups.