I've had the KS i900r since it first came out. Aside from a little stiction when I first got it(fixed by removing a bit of bearing material with Scotchbrite), it has worked flawlessly. Can't imagine riding without it.
I take care of my stuff and have done regular lubrication and maintenance on the seatpost to keep it working smoothly.

If anyone is interested in how to take care of your KS seatpost, I've posted how to do it HERE. Plenty of photos, should be pretty easy to follow. Complete teardown and maintenance can be done in an hour or two without any special tools.
I take care of my stuff and have done regular lubrication and maintenance on the seatpost to keep it working smoothly.

If anyone is interested in how to take care of your KS seatpost, I've posted how to do it HERE. Plenty of photos, should be pretty easy to follow. Complete teardown and maintenance can be done in an hour or two without any special tools.