More stops damages the product for most passengers doesn’t it?
The sleep period is pretty short with out the disturbance of stop and start, and people getting up and opening doors etc,
I found the soundproofing/ride on the Mk5s to be ample for this not to be a problem. Then again, I downed a couple of cans to aid sleep....
Maybe. I assume the Watford stop is there for some theoretical legacy view that people would get a taxi transfer from Heathrow to catch the sleeper (although in this day and age it would make more sense to fly to Scotland in the first place). I have no idea what the size of the potential market for people joining at Milton Keynes would be.
I don't know, but I suspect bigger than Watford. It's stopped at the latter for so long people have probably forgotten why. It probably just stems back to the days when most ICWC trains did stop there.
Watford was always traditionally a railhead for the home counties via the M25. However, that harks back to the days of normal passengers picking up paper timetables and spotting the Watford stop, which (despite enthusiast protestations) is not how most folk plan their journey any more. Plus M25 congestion being a deterrent.
MK is probably a much bigger railhead these days for the Oxford-Cambridge arc. (Aylesbury, Bedford, etc). To the point where, on paper*, the Watford stop could be sacrificed for MK (given that Watford passengers retain an easy change of train)
*Noting that this may screw up pathing.