Kepp in mind that there are three main binding points for strings on a Stratocaster - the bridge/saddle, the nut, and the string tree(s). If you are wanting to help your guitar stay in tune during bending and such, make sure you address all of these binding points at once. With a roller bridge saddle, you might find that you can bend a bit farther and easier, but this will cause the string to bind more at the nut and at the string tree(s) if they are not also roller type components.
Just a thought.
