Comparing the NIV and TNIV for standard English
In a large number of cases, the TNIV and NIV wordings are identical. But let's look at some of the differences between the NIV and TNIV which I have noted in my study.
In Matt. 13:38 I consider that TNIV "the people of the evil one", in contrast to NIV "the sons of the evil one," is a more natural way to communicate the Semitic meaning 'belonging to' of the original idiom. The TNIV rendering also communicates the original meaning more accurately to English speakers who do not know that Semitic "sons of" meant 'belonging to.'
In John 12:15 TNIV "Daughter Zion" is better, IMO, than NIV "daughter of Zion," which sounds like it is referring to a female whose father's name is Zion. The TNIV wording is still not as clear as it could be that it is referring to the people of Jerusalem, but this is probably one of those places where the TNIV translators feel that this information needs to come from teaching.
Although my most recent research has been to evaluate whether or not wordings are standard English, I sometimes have observed that one wording is more accurate than another. In 1 Cor. 7:1, I consider that TNIV "It is good for a man not to have sexual relations with a woman" is more accurate than NIV "It is good for a man not to marry." Both words, of course, are standard English.
In Eph. 2:3 I gave both NIV "objects of wrath" and TNIV "deserving of wrath" a "1" for being standard English. But this is a case where I would prefer to assign scalar numbers rather than binary ones. The TNIV wording is better English.
TNIV 2 Thess. 3:10 "Anyone who is unwilling to work" is a clear improvement over NIV "If a man will not work." Other recent English versions, including those which strictly follow the complementarians who created the Colorado Springs Guidelines, also correctly translate the gender-inclusive Greek pronoun tis here as "anyone."
It is not standard English to have a testimony "in" yourself or even in your heart. In 1 John 5:10 TNIV "Whoever believes in the Son of God accepts this testimony" improves upon NIV "Anyone who believes in the Son of God has this testimony in his heart."
What are some other improvements to the quality of English that you have noted that the TNIV has over the NIV?