I got my Ninja for Christmas from Walmart and have been using it at least once a week since. If you cook something on the low/crock pot setting, you can't set it for more than about five hours or it will burn. The buffet setting doesn't keep the food warm, and my digital numbers are now missing part of the number.
I've used the stove top setting to brown meat, and that worked fine. I haven't tried the oven setting, so I don't know how it does. It's a great idea if everything worked right, but have to say I'm disappointed in this.
Bottom Line: No, I would not recommend this to a friend