I had one before I got my full-suspension bike. Other than the fact it is heavy as a brick, it works amazingly well. It saved my back lots of pain, and really takes edge of roots and rocks. I thought it was well worth the money.
"Whatever happens.. don't fight the mountain." Ben Stiller's friend
I used one for about a year to a year and a half.I had hurt my back really bad lifting at work, it keep me in the saddle.As the back got better I started feeling pain only after I rode.I found that when in the seat climbing that I had a lot of up and down motion working my back and robbing me of power.I put a solid seat post back on and the back stopped hurting as much after my ride.I know it is kinda strange that it helped then it started hindering me.
I will let you use it to see if you like 27.2 seat post diameter.
I've have a Short Travel "ST" version on my hardtail for going on 6 years now. In the past I've used everything from Rock Shox to Answer Body Shock to Tamer to the LT Cane Creek Thudbuster. Cane Creeks are the most durable as well as have the least amount of lateral play. The ST version is all I need, even in the mountains. It does rattle around while standing but if you rest your leg on the tip of the saddle it goes away or get one of the neoprene boots to cover it.. Not the most ideal of suspension options, but a great one for hardtails and 29ers without the weight penalty and complexity of suspension. As far as suspension posts go, I think it's the best option out there.