There are times when I've considered taking the sleeper from Stirling to London for onward travel to Oxford. The trouble is, by the time I buy a good priced Advanced Purchased ticket to London, then pay for a peak price ticket to from Paddington to Oxford as well as cross-London transfer the time lag and cost usually means it is better not to bother and just fly down in the morning. It is probably very similar for many people whose final destination is not central London. Once the E-W link opens, would there be value in stopping to set down only up at pick-up only down at either Milton Keynes/Bletchley? Providing that regular timetabled trains operate a service that would connect to the sleeper, I suspect it could open up a wider market.