To reiterate what others have been saying this pair of earphones: The overall sound quality is astounding, the soundstage and separation is phenomenal, the build quality and packaging is world class. It even has a integrated mic and volume controls to supplement your phone! 
 
I liked them SO much I have 3 pairs of them as backups just in case Xiaomi discontinues them. It is THAT good. 
 
Just like any in-ears YMMV with the sound isolation and tip comfort, but this is a USD $20 piece of equipment to cry out loud. You simply cannot go wrong unless of course if you bought fakes which unfortunately are everywhere on the net. 
 
If you have read this and can get the real stuff easy like in Singapore or China yet somehow still want to stick to crappy iPhone/Samsung earbuds, shame on you for doing your ears a major disservice.

Like many others, I was very skeptical about the Swans M10 2.1. How can something that retails for only around US$60 in China get such rave reviews in the Internet audio circles? So I bought one to check it out, after all it was only US$80 from where I live.
 
Sure, it has wooden enclosures unlike the downright nasty plastic used by at this price range, but it still looks kinda cheap to me. The satellites themselves barely weighs enough to qualify as a paperweight, and the 3-inch woofer suggests the low-midrange is gonna suck...hard. The powered subwoofer unit only has a 5-inch driver? Are you kidding me?
 
Until I hooked them up with the subwoofer on the desk, connected to my PC by my cheapo Sabre USB DAC. 
 
I was completely blown away by the sound which vastly exceeded my expectations.
 
The tweeters produces mind-blowingly clear and detailed highs even better than my Wharfedale Diamond 210 bookshelves, and the initially anemic looking 3-inch woofer is no slouch either with clear midranges. The overall sound signature is forward sounding that put vocals right up to the ears. The subwoofer delivers a clean and tight punch that stays faithful to the original recording but also at no point during my listening sessions that the M10 muddies the sound unlike so-called gaming speakers that farts out muddy bass from the sub to vibrate everything in sight to impress people who know no better in sound quality. I have a Klipsch Promedia 2.1 and the M10 makes it an absolute ripoff in comparison by producing better sound at ~1/3 the price.
 
Just before anybody says I'm over-hyping the M10 too much....I'm not saying the M10 is going to match the sound quality of $500+ setups but at theor asking price it is an absolute steal if one can live with the drawbacks as stated in the header. Run, not walk to grab one if you can have it for cheap.