Conclusion: These headphone definitely block outside noise and are comfortable to wear and have good sound quality. The only thing I do not like is when I'm wearing them while exercising any movement of the cord is amplified in the ear buds. For that reason alone I would not likely spend the money to purchase this item again.
Conclusion: I really fell in love with Klipsch S4's with my black s4i's but those broke after about 1.5-2years of use (rough gym use included) and couldn't really imagine using any other headphones. Came across this website with a nice discounted price for the white s4's and never looked back :). Also bought the Reference s4i from here for my girlfriend, she really loves those as well.
Conclusion: These earphones are an excellent value. I obtained these earphones which work with a wide range of music in clear highs, middles and lows, with no distortion or buzz. I use them frequently when exercizing. I can crank up the music and tune out the world. They are so good, that sometimes I worry about my eardrums. That is when I turn the music down. They are well made, and durable. I would buy another set if the need arose.