Someone happened to leave a copy of a TNIV New Testament in my daughter's Wednesday night class at church, so I looked at it. I only managed to read the first 8 chapters of Matthew, so I can't give more than a rudimentary opinion on the TNIV.
I keep an NIV Bible on my desk at work. It happens to be a low-cost, no-commentary Bible I bought in high school, since I was tired of fighting the King James in my head. As I've gone along, I've kept that NIV for personal study and reading, but IMHO it's closer to a paraphrase than a literal translation. When I want to get closer to the autographs, I will go to translations like the Analytical-Literal Translation, the LITV Literal Translation of the Holy Bible, or Young's Literal Translation. I discovered E-Sword several years ago, and regularly use it to compare multiple translations of the same verse to get a feel for the actual Greek.
I don't like that contemporary English is abandoning the masculine collective. Without a generic way of indicating a single person of either gender, many verses of the Bible will be less clear. I am not certain a Bible translation is the right battleground for this fight, but it is the right fight for language conservatives to make, and it's not clear that there are many other battlegrounds left.
I may well end up with a copy of the TNIV, but if I do, it will be as another storytelling Bible. It will not enter my collection of "accurate" translations, but I'm not sure I feel the need to protest it too greatly either.