That's a totally fair point. I'm not entirely sure why most third parties are still using ~ in their documentation but it still seems to be the norm. I do like the definitive nature of -all.
IIRC ~all is the recommendation because hotmail/live told people to use ~all to prevent hardfails when hotmail's lookups timed out or if a particular mailserver IP was inaccessible during spam checks.
~all will result in your email being bounced around until accepted even if the IP doesn't match DNS records (more or less).
-all will result in hardfail if rejected by any TO mailserver.
