I am advocate of formal equivalence translations, but I am increasingly finding that the foremost defenders of the methodology just make bad arguments and honestly do not seem to understand linguistics. Ryken raises legitimate concerns concerning overly free translations, but others are nitpicking and just choosing the worst examples to engage with to make a point. At places, he seems to he repeating arguments that would have been used against translations other than the KJV (e.g. simplifying language, paring down vocabulary, pandering to lowest common denominator, etc).
No literal translation truly communicates EXACTLY what the biblical writers originally wrote; you only get this from reading the original languages. Literal translations are never truly literal.
I felt this passage was somewhat instructive in at least demonstrating a lack of nuance in his Hebrew:
'Here is how a range of translations express the agreed upon meaning:
“Whatsoever he doeth shall prosper” ( KJV ).
“In all that he does, he prospers” ( RSV , ESV ; NASB similar).
“In all that they do, they prosper” ( NRSV ; NLT nearly identical).
“Whatever he does prospers” ( NIV ).
“They succeed in everything they do” ( GNB ).
Do these translations communicate the same meaning? No. To project prosperity into the future with the formula “shall prosper” is not the same as to assert the present reality that the godly person “prospers.” To locate the prosperity in the person by saying that in all that the godly person does “he prospers” is different from saying that “whatever he does” or “they do” prospers. To paint a portrait of the godly person (singular) communicates a different meaning from the communal or group implication of the plural “they.”'
Frankly, there is a translation difficulty at Psalm 1:3 that Ryken glazes right over and tends to attribute to poor translation philosophy. The imperfect tense could be understood as either present or future (prosper/prospers), while the subject of the verb itself is ambiguous and could grammatically refer to the righteous man (he prospers) or the relative pronoun (whatever... prospers). Hebrew also uses singular to stand for a general principle in a way that English commonly uses plural groups to make general statements. All translation is interpretation to some degree, and sometimes translators simply have to make a decision because they do not have the option of being ambiguous in English in the same way that the Hebrew is.
In my opinion, the English language has been so influenced by the legacy of the KJV that formal equivalence translations are generally to be preferred. I just wish the argumentation wasn't so overstated and peppered with poor linguistic understanding.