One of things I didn't like about them is that they're bulkier than your typical earbuds. You're also meant to wrap the cord around the top of your ear and around back of it; the cord is stiffer at the top and has memory wire that you form into a sort of hook around your ear. It can require a little extra time to get everything to fit properly, which may bother some people.
On the plus side, the Sport-Fi S6 package comes with a lot of extra accessories, including an extension cord for when you're not using the earphones with the armband, and a nice carrying case, which is a tad large but does hold the armband. I should also point out that the armband pocket is fairly compact and isn't designed for larger and longer phones like the Apple iPhone 5 and Samsung Galaxy S3; it seems better suited for the older iPod Touch models (not the latest version), the iPod Nano, and the iPhone 4/4S, which still sticks out from the top a bit.
In terms of features, the one thing that's missing is a built-in microphone/remote for making calls.
The Sport-Fi S6 earphones are the type that some people are going to like a lot and think sound great for the money. It really depends on the shape of your ear and how tight a seal you can get along with a comfortable fit. Unfortunately, I had a hard time getting a good fit, and I'm also not a fan of earphones that require you to wrap the cord around the top of your ear and then behind it. My other small gripe was that while the S6s seem durable enough, they look a little cheap. That's fine if you're paying $20, but when you're paying more than $40, it's a little bit more of an issue (MEElectronics' M6 earphones sell for closer to $20 online, so that may ultimately be the better deal).
All that said, you may be among those who find that these work well, and they do come with a nice set of accessories. So, in the end, while I wouldn't buy them for myself -- I'd probably spend more on something like the