KJVO is legalism at it's worst and silly at the best. On the scale of translations the King James is almost on the end of the scale for a Thought for Thought translation but I teach from it because I teach the G.O.M. (Grumpy Old Men's) Class and few of us enjoy my study bible, the NASB.
The last time I checked the NASB was next to the nearest for a Word for Word translation. I love the word for word translation because it makes it easy for me to read and then pray. I came to the Faith using the KJV but to fully comprehend it requires a good deal of external study that, very, few will ever commit to.
The statement that it is in English is an incomplete and thereby false statement. It is translated and written in 17th English and requires the twentieth and twenty-first century man and woman to study the English of the day it was recored. Just one example is, perhaps, the most frequently misused scripture, "Thou shalt not kill." The translation of that verse in 1611 is correct for that time, not so for today. Translating it today it reads, "You will not murder." If it were 'you will not kill,' I, a combat veteran, would go straight to Hell and I believe God would never have run me into the ground so I could serve Him.