Spodman,
Because of occassional radar outages we do encounter some non radar situations so we put the acft regardless of equipment suffix on airways and we use position reports to keep track of them and to determine when to call the next facility with a non radar handoff. Granted GPS or RNAV equiped acft can give us better positions reports but we still utilize the airways during non radar situations.
When all the approach controls get STARS we will be able to mosiac from up to 12 different radar sites so non radar situations should occur a lot less.
We have several airports with 15 NM of our boundry that we descend arrivals to 5000' and many times the En Route center can't see the arrival so we will terminate radar service at our boundry and switch comm to the center. The center controller will block the airspace from 5000' on down until the acft cancels his IFR.
If you ever get the chance you really need to visit the US and come and see an En Route center, and Radar Approach Control to get a good idea how we operate here.
Mike