I previously had the mx75s, these worked well, had good sound quality, the only problem was that they ear adapters were quite rigid and became uncomfortable and sore after a while. Then one of my earphones stopped working and the wire had become to come away at the base.
So...with the new twist to fit system something that i wanted, i found these. They are almost the same as the mx75s, and come with the same kit - a carry case, cable clip, ear adapter set, earphone rings and sponge covers. But senn have improved the ear adapters and made them more flexible giving them a more comfortable fit and rubbing doesn't occur like on the previous peices.
An excellent piece of kit for the gym especially if you find that your earohones fall out all the time. The sound quality is awesome, and the bass is relatively solid (not hugely "boomtastic", but good nevertheless). Very good for the price, well worth the money, buy! =)
The only problem i now have is that the orange colour scheme doesn't match with my bright green nano like the 75s did! =D