It depends greatly on the room you are in and what your goal is. I wouldn't trade my projector for a flat panel, or my flat panel for my projector. They both have a time and a place of use. I watch major movies and sometimes hockey and other quality HD viewing on my projector. Stuff of some significance. My 161" screen dwarfs my 85" flat panel display, and I have it in a light controlled space with black drapes up to help with reflections (some). It's not a perfect room, but it's extremely fun. I also got a projector which is several steps better than a entry level DLP model. This matters a great deal when you are talking about black level performance.
In a really dark room, a good LCoS projector can look very good. Not OLED good, but still, really good. Plus, you get a lot of added potential size.
I will say that there is no such thing as using a TV for home theater. A big TV, no matter how big, is still just a TV. It feels like a TV, it looks like a TV. A projector with a front projection screen FEELS like a theater. It looks like a theater. It can be enjoyed as a group like a theater.
There are some who have used projectors who can't imaging using a TV again. There are those who have used a projector and didn't like it at all. But, for most, they share responsibility between TVs and projectors. Which is, how it should be IMO.