The rail mounts to a replacement bolt locking cover plate, which slips right in to place. You only have to field strip the receiver/barrel assembly from the stock, which is very easy to do. Then you just screw the rail assembly in to the plate, and tighten down the adjustment screws.
Also, the rail is raised above the integral Ruger scope mounting points, so that - unlike the factory mounting system - you can still use the iron sights while a scope is mounted. It also prevents hot brass from being ejected in to the bottom of your scope.
The whole assembly seems pretty solid, and it's all supposed to be built for semi-auto centerfire rifles, so the shock from rapid firing the guns shouldn't affect the scope zero. I'll check that out at the range tonight and post if I find differently.