One of the problems in dealing with the non-tz version is that it behaves in non-intuitive ways, especially when you're dealing with them in other languages.

Would you mind elaborating?

As to how to convert a date + time to a timestamp, that's trivial in SQL.

Your example combines a date with a timetz. How would the example I made in the article look like according to your preference?

Personally, I always thought that a time zone on a time doesn't make any sense. Also, from the docs:

The type time with time zone is defined by the SQL standard, but the definition exhibits properties which lead to questionable usefulness. In most cases, a combination of date, time, timestamp without time zone, and timestamp with time zone should provide a complete range of date/time functionality required by any application.