Yes, I'm aware of that. Sorry, bad wording. I choose btrfs because it's simpler to setup. It is also lighter on memory for uses on personal machines. I know ZFS can work with less memory but at a performance disadvantage.
I found the need for a plenty of RAM a little overblown for ZFS. My anecdotal experience: I repaired my home file server replacing faulty RAM with 2G stick (because that was only spare piece I had) as a temporary solution. But as it often happens with temporary solutions it lasted longer, for slightly less then two years. Prefetch feature was automatically disabled, but there were no delays which my perception can register. I suppose speed degradation would be visible on heavy-lifting server, but exactly for personal use one doesn't need any special amount of RAM.