We know that she prizes "any burst of feeling, any warmth of indignation or delight", "the frank, the open-hearted, the eager character beyond all others."

That is why she fell in love with CW 8 years ago. And now delights in Admiral Croft. And has warm feelings for the Musgroves.

And why she is (probably) bored with the stupidity of SW and Elizabeth's company, which revolves ad nauseam around superficial things.

I think she is disappointed with LD and Miss Carteret because they're too... technically/robotically-gracious. All politeness and civility. None of the open-heartedness and eagerness she admires.

As opposed to Mrs. Smith, who, while not exactly providing intellectually stimulating conversations, remains spontaneous and warm and true--"in the course of a second visit she talked with great openness". By the time they got over their awkwardness, Mrs. Smith freely talks of gossip, her stressful experiences, etc.

The group of people Anne likes is a cheery, spontaneous, wholesome bunch, as opposed to the more stifling, formal, agreeable (in the blandest sense) crowd of LD. (I remember how bewitched Anne is at the hospitaity at the Harvilles, which is so unlike the "dinners of formality and display" at Kellynch.)