Chris doesn't like the Mac Mail app, and PGP tends to screw things up. Leo has been making PGP keys since 2005, but when he made them, he didn't keep track of the revocation password or get a revocation certificate so he can't revoke old keys. It's always best to use the most recent key. The way to verify that encrypted email with Leo works is by going to his website at leolaporte.com and checking the PGP link, which is his most current key. PGP doesn't work with the updated macOS Sierra Mail app, though. Leo actually doesn't use Apple Mail, he uses Mail Mate instead. It's not free, but it does have a free trial.
Chris' main problem with Apple has been that speech recognition is using well over 1GB of memory in Activity Monitor. Leo says that speech recognition is one of those things that is memory intensive. Speech recognition has to keep a big vocabulary in RAM to keep up with it. Using 1GB if he's got 8GB is not a real concern.