Most biblical scholars claim that the King James Version isn’t the best to use today because of the archaic terms and non-usage of the latest surviving documents. Are there any flaws within the New King James Version?
You have the right scoop on the KJV, otherwise known as the Authorized Version. The principle problem with the King James is not the archaic words, although that is certainly a very large impediment for using this version to understand God’s Word. The biggest problems with the KJV are two-fold. First of all, at the time of this translation (which was really a revision of the Tyndale translation) is that it was based on only a very small number of Greek manuscripts, and the manuscripts used were from after AD 1000, whereas we now have over 8,000 Greek manuscripts, including complete Greek manuscripts from the 300’s AD and many partial manuscripts from the second and third centuries. The second problem with the KJV (other than the archaic language which probably needs a translation of its own) is that it is not based on the most recent scholarship. There has been four hundred years of research into Jewish culture, the Greek language, Roman/Greek culture and religion and many other topics. All this knowledge can be and has been used for create the far superior modern translations of the Greek New Testament into English and other languages.
Now, about the New King James version, I have used that one. I believe it is an excellent translation. It is based on very good scholarship. It is a phrase-for-phrase, rather than a word-for-word translation, which is fine, but it is good to keep this in mind as you read this translation. There are many good translations into English. My recommendation is that if you want to do a solid study of the New Testament you should get two or three different translations and use them in combination. I like the Holman Christian Standard Bible. It is the one I have been using lately. The New KJV is fine. You should feel confident using this translation.
I hope this helps.