Romantic leading man, or hard-as-nails detective? Find out just what Chris Noth thinks of his two signature roles.

CHRIS NOTH, who is known for both his role as Detective Mike Logan on "Law & Order: Criminal Intent" and Mr. Big on "Sex and the City," takes a break from doing double duty on the series and the new 'Sex and the City' movie to promote the mid-season finale of "Criminal Intent," airing Thursday, Dec. 13, at 10 p.m. on USA Network.

ET: How has it been balancing "Criminal Intent" with the 'Sex and the City' movie?

CHRIS NOTH: Crazy! It is pretty schizo. It is totally antithetical in subject matter and feeling. It is two different sets, although, for a movie, they cover an enormous amount of ground. They may not be doing eight or nine pages [a day] like we do, but they cover a lot.

Right now, I am so tired, I can't articulate. You've got to get eight hours of sleep for "Law and Order." 'Sex and the City' is a romantic comedy, so it is different in terms of timing. You are using a whole different set of instruments. It is like two different families. It was fun to get back to each one of them. Coming back to "Law & Order," after being in that world, was, at first, a little bracing. Then it was back to normal. Then going back to them after "Law & Order" was a little weird.

ET: Who do you feel closer to: Logan or Mr. Big?

CHRIS : It is like choosing between your children! Both of them are New Yorkers, just from different neighborhoods. I always joke with Big that I am going from GUCCI clothes to Logan's MO GINSBERG suits. But they are both really great fun -- great individuals with different points of views and different worlds. Our sets articulate that also. On 'Law & Order,' I think there is a little more testosterone. The 'Sex and the City' set is a lot more female oriented, with a lot more emphasis on hair and makeup.

ET: How do you keep it fresh?

CHRIS : I would say 95 percent of the job is the writing. With 'Sex and the City,' I always felt that MICHAEL PATRICK KING (producer/writer/director) is our contemporary NOEL COWARD. When you have that kind of writing, you float on that. The chemistry between my partners, SARAH JESSICA PARKER on 'Sex and the City' and ALICIA WITT and JULIANNE NICHOLSON on "Law & Order" helps me to travel through the geography of those shows in whatever styles those shows demand. That helps to keep it fresh.

We've got new writers on "Criminal Intent." I think we've got a different show than it was, at least on our side. The other side was more what it originally set out to be with Goren (VINCENT D'ONOFRIO) being Sherlock Holmes and all that stuff. But we're a real partnership and an ensemble show on our side. It's a lot of fun doing it. I think Logan and Falacci (Witt) have a great chemistry, because there is an energy and a discovery process going on and that all helps keep it fresh.

ET: Are you happy with the way Big is being portrayed in the movie?

CHRIS : Yeah, I am very. I can honestly say from the writing and what we've shot that I'm pretty happy.

ET: Is it a good resolution for your character after all the years on the show?

CHRIS : It's a continuation. I'm not sure anything needs to be resolved. They're a part of each other's lives, you know, through all the twists and turns. And there are a lot of different twists and turns, but he's a big part of her life.