I'm thinking of upgrading my router table to use the Incra LS positioning system. I currently use this type of fence on my table saw and love it. On the table saw, after positioning the fence, you lock it in place to a rail at the front of the table. The router fence doesn't look like it has this type of lock so it seems to me that the fence won't be nearly as rigid. Is this the case? Other brands of router fence lock in place to 2 tracks so they should be much more rigid but they don't have the convenience of the positioner.