Angrel.
Having spoken to a competent 'air tafffickker' yesterday on the subject of radar-to-visuals (nothing to do with the F15 CFIT), he assured me that an aircraft could be cleared to a lower height on a RIS than a RAS. This was because on a RIS we can be cleared below the radar vector chart. Surely this is why you can get a RIS as soon as getting airborne but before you are high enough for a RAS? I'll double check with my contact, but this does concur with my understanding that you'll always get lower on a RIS!
As regards the 'blah' about terrain clearance, this has gone from ATC phraseology where I work, maybe a local procedure. Do I really need constantly telling something that is SOP? I think not.
H Peacock.