But over time, I think I discovered a better way: a script in my $PATH.

Benefits of scripts over aliases:

• No reloading; changes are picked up immediatly
• Choice of programming language
• Complex logic can be implemented
• More portable between shells

Aliases have certain benefits:

• special syntax (cd.. for cd .. with space)
• completion
• conditional definition
• easier to bypass with unalias
• brevity: it's a one liner
• performance: alias are 100x faster.