It's pretty fun, I only did it for a short period of time but the funny thing is that the picture quality was actually better then on my laptop screen.
Max res was 800 x 600 on the tv, which allowed me to up Pixel shading and Vertex shading without loosing much FPS. I only tried monitor mirroing, I wonder if its possible to run the laptop in closed lid mode.
Anyways give it a try its like playing on an XBOX but with keyboard and mouse.