The first set I had delivered had about 6 or 7 dead pixels in the middle of the screen. I had this replaced within the week, the new replacement has one dead pixel off to the right hand side. Only can be seen by sitting very close to the set, so I'm not too bothered by it. I thought it might show up on the 360, but it was fine.
I suppose it all depends on your own personal Pixel Tolerance!! (also if they are in the centre of the screen it can be VERY distracting).