I think there are two parts to awesome care.
The actual care received/given and the appearance of quality care.
For instance if the barn is old, the stalls floors are uneven bare ground, and there's old hay on the grounds and baling twine or litter every where and un picked piles of poop, it doesn't matter if the management is pampering my horse every second, b/c I don't get the feeling that the details are being attended to when I'm not there.
I was at the best barn before I got my own farm.
What made it great was that the barn owner was always doing something to better the property; painting, power washing, repairs etc.
She didn't nickel and dime services, like taking fly masks on and off or switching out blankets, spraying fly spray in the summer, or feeding suppliments, etc. It was included in the price because in her words, "the care of the horses was the first priority" and she didn't want something like "$15 a month for fly masks on/off and AM fly spraying" to be a ridiculous issue. The horses need it takes 1 minute, twice a day and it's in the best interest of the horse and NOT the "bottom line."
The barn owner would text me ANYTIME anything was wrong, weird, odd or off, and occasionally if my horse was being cute or silly email me a photo during the day.
She would have barn parties and group ride nights or plan outings. The best were actually vet calls. She threw these twice yearly parties, for when the vet would come out to vaccinate all of the horses, and float teeth in the spring, so that we could share the cost of the vet call, and it was a fun day .
She would constantly ask me how I thought things were going, asking for feedback and she was genuinely nice.
Because she put so much effort in to the extra details and I coulud see the effort her and her stall cleaners put in to the horses and the facility when I was there, I trusted the quality of care my horse received when I wasn't.
She never has openings due to her extensive waiting list. She has **** near no turn over. I was there for two years and never knew anyone who left.