There are (more than) two things that I love with SQLcl : formatting and aliases.
I work with several Grid Infrastructure clusters, hosting hundreds of databases accross multiple nodes. I am very often typing the same queries, this is where SQLcl comes in handy. You can use a
login.sql file with SQLcl, just like you would use it with SQL*Plus.
After some tests, I found out that SQLcl looks for a
login.sql file in directory and subdirectories pointed by the environment variable