Have been using that weekly since probably 20 years. Will change your life :)

My other favourite is I very often SSH with -v to figure out why the connection is hanging, you rapidly figure out if DNS is failing, the TCP connection doesn't open, it does open but no traffic flows at all or it opens and SSH negotiation starts but never finishes. You can learn a lot just from this about what is wrong.

Also helps with auth failures, I've used it several times with co-workers who can't figure out why their ssh key isn't working. It lists the keys out and some extra information.