A320: Our company descent profile is cost index cruise in to 280kt. Usually about .78/280.
In order to try to maintain a reasonable profile (not super shallow with ATC steps) I prefer to reduce cruise speed first to a comfortably low speed, then if necessary use that as mach for descent into 280, then start reducing the 280 KIAS. Often you are 10 kt above min clean all the way and still cant make it and thats when a vector helps. Curious though why an orbit (about 2-4 min delay) is rarely available? Is it due to conflicting airways laterally?
ATC has a record of standard speeds for most companies, as yet no requests have been made to vary these 'profile' descent speeds as far as I know (as a pilot pleb). Terminal arrival speeds should be standardised fairly soon though, all going well.