I was wondering how well TPU would work. While it's a flexible, it's pretty sturdy stuff. If you print using a near 100% infill, it's not as flexible as you would think, and the layer adhesion is pretty amazing. I've tried to tear apart TPU temp towers in the past (I tend to break my first temp towers to see how well layer adhesion works) and I've never been able to break one (without tools).
I guess it ultimately depends on what you're wanting to print. If you need a solid piece, then TPU obviously isn't going to be your first choice, but it might be worth considering if a little bit of flex is acceptable.