I'd assume that a hard border between the two would be fairly unpalatable and possibly not even practical.
I’m not sure that that is going to be true and I assume you are making a comparison with the Northern Ireland border here. Allow me to very briefly highlight the problems of the Northern Irish border, the only current land border the UK has.
In its current state (both sides EU and Common Travel Area (CTA) members), both goods (Common Market) and people (CTA) can freely cross the border as they desire and no checks are necessary. In the Hard Brexit scenario where the UK does not remain in the Common Market or a customs union, the free movement of goods would be restricted—but people can still pass freely thanks to the CTA. Obviously, people if unchecked can bring goods across the border (which would be smuggling and evasion of customs/taxes), so the people need to be checked to ensure they don’t. This requires border posts or inspections of some sort which, as anybody who studied (Northern) Irish history for 5 minutes should immediately recognise as a pretty bad idea™.
The principle reason why the Irish border is a problem is the history, not the requirement to introduce any kinds of checks. The England–Scotland border has a very different history. The two countries had been fully independent until 1603 and then two kingdoms under a personal union until the Act of Union in 1707. The border between the two has been recognised commonly as a line on the ground for centuries and is even mentioned as one of the oldest extant borders in the world; even after the Act of Union, everyone has always agreed on what is on which side of the border (minor exceptions apply). While in modern times there is little difference between either side of the line (the most obvious probably being the possibility of encountering £1 notes north but not as likely south of it), it would not be hard to reestablish it, i.e. make it more noticeable.
Placing border posts there would be annoying to travellers and people living on the border (as it always is) but since there is a clear ‘English’ and a clear ‘Scottish’ side (rather than a big ‘Irish’ fudge) it is very unlikely for these checks and posts to incite anything even remotely akin to what happened in Ireland. In addition, a Scottish referendum would come first, so the people on the northern side would have had their say on the matter and approved of it as a whole.
For people, the border could well remain very open as both sides could remain in the CTA. Only a simple photo ID like a driving licence would likely be needed to cross it and it would basically be like crossing the channel. For goods, potentially more elaborate inspections would be needed due to the different customs areas (again assuming a Hard Brexit scenario). Not like anything that has happened anywhere in England recently but not unheard of at other European borders. The overall result would be a little inconvenience as I have already mentioned.