I finally got frustrated enough with the quality of the earbuds I had been using for years that I replaced them with these. Immense improvement, and I'm very happy. Great value. What follows are some notes in case you are also thinking about doing this.
First and foremost, listen to opinions of people who know sound. These were recommended by a musician friend, so I knew they wouldn't suck. Reviews from other musicians talking about things like soundstage depth and presence at various frequency levels also helped give me confidence this would be a good move. My only hesitation was some reviews saying there was not enough bass. As a bass player I can tell you these are just fine. There is great depth and good representation across the low end spectrum without any perceptible artificial "punch" being notched up. The representation of the recording is impressively exact. In general these are right on par with my stereo and my pro audio PA.
The big adjustment was the isolation. This is not to be taken lightly. When walking around with these, the vibration you hear through your bones from your foot hitting the pavement will be louder than people talking or cars going by. You will need to compensate visually. If you are blissfully unaware of traffic, and don't bother to look when turning corners, these are not for you. It's like you are wearing those foam earplugs you use for ear protection, then replacing the residual muffled sounds with full depth music. It's trippy and fun, but don't go for a Darwin award.
The other options are headphones that let ambient noise in. Of course if you turn those up loud enough to block outside noise, then it's the same thing except that you may be damaging your hearing. If you don't turn them up loud, then the bass is going to be lacking. If you are doing books on tape, music without much bass, or you don't mind the quality loss from some punchy sport headphones, then that might be a better option for you. For me, I was done with that approach.
Be prepared to have it take some time to learn how to put them in. It gets much easier with practice, but it is not fast. If you need to replace the stock foam earpieces, you can damage the ones on there if you are not careful. Freeze them in a baggie first. If the stock one's fit, then use them. The earbud with the red dot goes on the right.
For me, this was all well worth it. Annoying loud morons on public transportation? Gone. Focus on what you are reading in a noisy environment? Oh yeah. Comfortable for hours, and great sound. HTH