I've been doing some more video encoding tests recently, using H.264 in Handbrake on my PC. Just tested the most demanding video I've encoded yet. LOTR Return of the King Extended Edition, which is split across 2 DVDs with no special features on those discs, giving this title a very high video bitrate which makes it a good test. Compared chapter 18 which is a great test as there's lots of smoke and other things which will push an encoder to the limit. Definitely in this particular example there were notable differences between 500kbps single pass H.264 and 1000kbps two pass H.264. In the lower bitrate example there was some obvious artifacting in several areas of this chapter, even around static things like actor's faces. This was probably caused by the presence of smoke, etc, in the scene. The 500kbps was still watchable but the 1000kbps example looked far more accepteable for more discerning viewers.