V.B.
We only have the Ninja. Husband loves it for his daily smoothies. I can't really say about other uses, b/c honestly, that's all we use it for. Every. Single. Day. And have for over 2 years now.
My only issue with it (aside from being insanely loud, lol) is that it is really large. I did not buy a unit with a smaller container to mix single serving size things (which, if I am not mistaken is what Nutri-bullet is specifically designed for, right?). Now, they make the Ninja with single serve attachments, but at the time we bought ours, they weren't available, or at least not at the store where I bought it (Bed Bath & Beyond with the 20% off coupon).
I have a friend who makes/mixes her banana bread recipe in it instead of using a regular food processor. Don't know if that helps you or not.