What are the major criticisms of the NIV?

While researching for [this answer](https://christianity.stackexchange.com/a/60491/16938) and reading different posts on this site over the past few days, I've come across some criticisms of the NIV I'd never heard before. I've seen articles claiming that it changes the Bible to make it more friendly to homosexuality, but these claims were more general and more significant. For example, the one that stuck out to me the most was where someone said that the NIV translators knew no Koine Greek, just modern Greek, and that they used two secular translators to translate the NT into modern Greek. These are some pretty serious claims. I've never liked the NIV myself, but that’s never been anything but my personal preference. I'd link to the places I saw these claims if I could remember. What arguments exist against the NIV? I'd like to find reliable references if at all possible. I’m not looking for small, minor issues like [a few missing verses](https://christianity.stackexchange.com/questions/13962/niv-hidden-bible-verses) . I’m looking for larger, more significant problems that could conceivably affect the integrity of the text as a whole. I'm not just looking for valid arguments; I'd also love to hear about any well-refuted claims against the NIV, so long as they had some intelligent basis in the first place. I know this question seems a bit open, but if any of these claims are true, I want be sure to avoid using an unreliable translation of God's words. I’m sure the same goes for others on this site and across the Internet.