I had one of these (Rem 700 version) for a couple of months and had some problems with it.
1. If you have older eyes and have trouble seeing up close, the level will be a blur.
2. If you use low rings and or a short scope, the power adjuster ring will interfere with the bubble unless you move the scope back to avoid it.
3. I had a bolt on level (on the rail) at the time and the two didn't agree what level was. At the time I did not have another means of leveling the rifle so I don't know which one was right.