We might just come back to the choice of East Coast over ScotRail, especially in first class, and why the OP is entirely right to look at this option even if there are technically slightly better times available with ScotRail. The ScotRail first class service offers slightly more space, a separate 'cabin' and free refreshments, amounting to tea, coffee water, juice (sometimes) and cheap unhealthy snacks. Bear in mind that paying customers will often get better versions of what first class customers get 'free'. For that you pay what is normally a spectacular premium.

Usually cheaper, and often much cheaper, the East Coast service offers far more space, and much better food and drink - depending on the time of day you will get a proper meal and real drinks. Wi-fi is free in first class (it's free for everyone on ScotRail, *if* they have it at all on the train, and not all of them do, yet.) If you have any flexibility at all on times, it's a no-brainer.

Despite all that, East Coast is doing very well financially, as well as being well-liked by its customers, but as it results from the enforced state takeover of a failed franchise, and is state-owned, it is therefore anathema to the unspeakable Westminster ideologues; its days are unfortunately therefore likely to be numbered, to be replaced by a shiny-business-planned POS from the likes of Serco.