I had to replace a pair of MDR-EX51LP because one side gave out after 6 months of rugged use. Not blaming Sony for that even if many have complained about it. I thought I would upgrade to the MDR-71Sl cause the number is higher right? I have these in my ears now since they were delivered today. Sound is great! Crisp high notes and decent not deep Bass. If you get new earphones you should get in-the-ear style like these. They are VERY comfotable. My problem is that I use these at work and wear them inside my coveralls down to my pant pocket. The cord on this is only long enough to reach my shirt pocket. You do get an extension cord, but I don't want that! The jack will either get pulled out or be in the way when I carry things. If you need some cord length past your Chest or Arm, get the 51's. They use the same 9mm driver and I can't tell much difference in sound.