I get these ksc-50 's to replace my aiwa hp-a091 's which break , as well as my panasonic headphone . I must say , these can ROCK !!  -- comfort -- these thing be really nice . they have a spring in the connector to easily slip they on . once they be on , you 'll soon forget they . I have hear that these will not work for people with big ear . I have normal medium ear and they be a bit loose . the pad be thick -lrb- without go beyond reason -rrb- and be very soft and comfortable . the clip be also flexible . I personally would not use these for exercise . they be a bit loose , and I think they would fall off . it be better to get something more secure like the Labtec curve-495 's .  -- sound -- well , these thing be unbelieveable when it come to sound . literally , I can not believe they be under 20 buck . even though the speaker itself be farther away from you head than most headphone , they be still loud and proud . they literally require less volume from the device or computer and put out a lot of sound . in addition to the high and mid be very clear , these can have booming bass . the bass in these headphone be almost excessive , so I can not imagine what the closer fitting ksc-35 's be like . even thouugh the bass be loud , the range be still very low , and be still as clear as the rest of the range .  if you be look for inexpensive headphone that do not just get the job do , these be the one for you . you will not be return they . if they be right for exercise and you size ear be up to you .  this be a edit to my review : unfortunately , I take these to school today in my pocket in my pants . I do not know how , but they get dent very easily . I will be return they . you might want to try somethign more durable for school environment , other than that they be still good for exercise .