I feel comfortable with the usage of the "Holy Ghost" because I have a background in both the Douay-Rheims and KJV and have been cloistered in the schools/churches which used these translations of the 16-17th century period English.
However, "ghost" has taken on at least one popular nuance (occult) that is significantly different than the biblical word "spirit-pneuma" and is more akin now to the meaning of "apparition".
I don't believe anything of the sense of the Scripture is lost by using the word "Spirit/spirit" in place of "Ghost/ghost" if the whole counsel of God is taken into consideration.
Of the passages which Carl cites (Rom.8, 1 Cor.2, Col.1-3) the phrase "Holy Ghost" or "ghost" does not even appear one time.
Romans 8 contains "Spirit" 17 times.
1 Corinthians 2 contains "Spirit" 5 times.
Colossians 1-3 contains "Spirit" 1 time.
The narrative says it all concerning the manifestation and power of the Holy Spirit in our lives with the word "Spirit" and without the term "Holy Ghost".
The term "ghost" is related to germanic/anglo saxon "gheist", "gast", "gustr", from which we derive the word "gust" as in a "gust of wind" or a "manifestation" of the power of the wind.
So, in 16-17th century, closer to the English roots, there was cause for "ghost" as related to pneuma-wind and its power and manifestation (or His power for the divine defintion) but IMO it needs to be updated for the current generation of Bible readers especially the newly saved from the ranks of the "unchurched'.
But, I would agree with Carl in that "ghost" encapsulated into one word the nuance of the power and manifestation of the Spirit for their day and a certain beauty of the old English phrase is indeed lost.
However (again) the passages he cited, which the Holy Ghost inspired Paul to write, refrain from using the term.
HankD