I've been using the S9-HD's for the past couple of months with my 3G S. I love these headphones!! great sound quality good for working out and running. They have great stability even for skipping rope.
The range is funny, you can have the phone in your pocket and it will still connect and everything works well, put your hand in that pocket for a second or two and sound will cut out. In the gym though I can lay the iphone under the bench, go get weights, walk around and perfect connection.
I think the connection cut out issue many refer to is a bit exaggerated from my experience with the headsets. Even in the package Motorola explains the range of the headphones to device on the body. If you are really concerned, use an armband.
Sometimes depending on the exercise, when using a flat bench, you might find a bit of discomfort because of the back part of the headphones when lying down, but you can adjust them a bit. For me, it seems to be good in the sense it forces me to not bend my neck and keep my head flat.
The voice control is nice, but after a while you look like an ass speaking "next track". Having said that, I hope like others here, that the future software upgrades from Apple allow for better bluetooth control.
Sometimes the headphones have better connection than other times. I have had instances where pause and play do not control the phone at all. A power cycle on both devices seems to fix the issue. Also Voice dialing from the headset will result in loss connection from command to execution. I blame Apple more on this as it's a software issue with the phone rather than the headsets.
Last, there is a slight delay from iphone to headphones sound wise, but nothing that ruins the experience, unless your watching a number of videos with them.
Overall a great purchase and the most comfortable, best sound I have tried thus far.
