We have the sewer solution which is water powered and are quite happy with it.
http://www.sewersolution.com/
The hose is heavy duty and doesn't get holes in it and takes up less space. I think the only downside may be if you don't have a black tank flush you may not get this tank clean as you don't have the fast rush of water running out that you get with the 3' hose. Other than this it works great and we have had no problems with it.