] Yes, coaching inns varied in their service..

I expect the 18th century wasn't much different from our time when it comes to service. You could get good or bad service just like today.
I suppose that in those days shop people could more easily than today recognise when someone had money to spend,and so be extra attending.
Inns left much to be desired,but I don't think they were generally bad.
John Byng in his travel diares from the 1780-90s describe his experences with the various Inns and Ale houses where he is staying, and it's a mix of good and bad(it's usually the food that is the problem), but more often good than bad really.

Most of these are not the busy coaching Inns wich could be unpleasant,crowded and noicy. I suspect that toilet facilities could be a broblem. You recognise it? It hasn't got better ;-)

One thing Byng didn't like was after having stayed overnight and leaving,the waiters and maids would be standing by the door expecting to get a tip.
And if you didn't give anything you could expect to hear some unpleasant remarks.

I suspect that it was the same as today,a lot of people that don't know much about cooking or service are opening restaurants and hotels. I'm sure you have noticed.

He recommends the White Lion in Stratford Upon-Avon as
"a notoriously good Inn". I wonder if there still is a White Lion in Stratford Upon-Avon?

Leif Gn