I got these to replace the 'phones that came with my iPod Touch. I think the iPod earphones are too quiet, especially when watching video, which can have a very wide dynamic range. Watching video on an iPod in a noisy place can be frustrating, even if you've tried all the tricks to get the sound up.
So I bought these hoping they'd drown out the background noise, and even if they weren't actually louder, they might seem louder. In practice, not only do they seal out your fellow passengers on the train, they are also a lot louder than the iPod earphones to start with. so much louder that I nearly blew my head off when I first tried them! Top marks for loudness.
The next thing you notice is that there's masses more bass than the iPod earphones can manage. If anything, there's slightly too much, but I've never liked a bass heavy sound.
Perhaps as as result of all that bass, it seems to me that the treble is a bit subdued in comparison. But they sound pretty good overall. The sound is very 'tight' and 'robust' like a pair of good speakers - very clear too and detailed. If you travel by bus, you will notice a massive difference over your standard iPod 'phones. It's as though the bus is heavily soundproofed and all the passengers are whispering. It's almost surreal.
A major (but one-off) annoyance was the nuclear-bomb proof packaging. Before you buy, have a pair of goggles and a tool kit handy...
Inside the packaging (if you manage to get inside) you'll find three different sets of rubber plugs for different-sized ears. The ones already on were fine for me as it happened. There's an extension cable too, but the attached cable is long enough if you have your iPod in a jacket pocket. There's also a cable clip (clips to your jacket), a rubber thing to wrap your phones around and keep tidy, and a little purse-style bag to keep accessories in.
Comfort, by the way, wasn't an issue for me: I thought I might not like pushing them in my ears but they felt quite natural. One thing you may not like is that if you touch the wire against anything, it transmits noise quite loudly. You may need to keep still. Also, if you talk or breathe (...) you can hear yourself. Worst of all is that when you walk on a hard surface, every footstep you take booms through the 'phones. This could be a big problem for you if you plan to use them while walking.
But for making a bus or train journey more pleasant, these 'phones are light years ahead of the ones Apple give you with an iPod.