I tried them at Best Buy and I must say that I was VERY impressed by the noise cancellation. Repetitive sound or not, it canceled it out very well. Also, listening to the demo track, I found the headphones to be of a warm character and the highs to be a tad bit grainy. The highs were still not grainy enough for me to completely disregard them as travel headphones.
What are your opinions? Impressions, reviews, comparisons welcome =)