Counterarguments to "KJV-only"?

Some people believe the King James Version of the Bible is the only version English-speakers should be using, as it is the only inspired translation. (This is referred to as "KJV-onlyism.") Basically, the KJV-only position is that: - The Bible is God's word - God promises to preserve His word * E.G., [Psalm 12:7 (read this article)](http://www.kjvtoday.com/home/does-the-second-them-in-psalm-127-refer-to-gods-words) - This preservation is accomplished via a perfect translation (one per language) - The KJV is His perfect, preserved translation in the English language - The reason other English Bibles differ from the KJV is because those other Bibles have been tainted by sin and error **What are the main counterarguments to this view?** I am specifically looking for answers which would be convincing to an English-speaking Protestant with a high view of Scripture.