The saddle in adddition to looking ugly will, due to its thickness, change the position of your eye in relation to the centerline of the rifle. This isn't a big deal as you will probably always shoot the rifle with the same amount of offset.
The height of the cheek piece is dictated by the height of the scope above the bore, the idea being that your eye is centered in the scope while you are afforded a good cheek weld. If you have a large scope, you will be unable to use low rings. If the cheek piece prevents you from withdrawing the bolt for maintenance, it must be adjustable to drop it out of the way. Once the rifle has be cleaned, the cheekpiece can be returned to its proper height, so speed of setting the height is a non-issue.