I have been using the Steadicam Merlin with a DVX100b for about 6 months. It took about 2 days of serious work to get it dialed in and to become comfortable with basic moves but since then I’ve been totaly satisfied.
It’s critical that you get the initial setup perfectly balanced and you will contstantly be “touching up” the balance between shots but it’s worth the effort.
The overall build and quality are excellent. I travel with it on a regular basis and have had no problems. (I did get the carrying case with the foam inserts, but that was probably overkill.)