I actually prefer them.
They are a little harder to fit than standard mounts.
You kinda have to fiddle around a little to get them on as with the others the scope just sits into them, these ones you have to fit the scope 1st, loose, Then place the scope on and tighten up.
Easy once it's been done a few times, odd at 1st.
As far as are they any good though .... Yea, they are really good.