I would add that her approach to surprises is delightfully subtle!
I loved Quartet in Autumn so much that in our small town library I smiled at a shelf when I counted twelve additional Barbara Pym novels on it. I'm all set for a while. Plus I think the shelf smiled back at me.
(Morning After Postscript: Last night, reading Barbara Pym's diaries, part of a miscellany of her writings titled A Very Private Eye, I learned that she was, as she put it, besotted by Denton Welch; he is also one of my favorite writers. It figures.)
[It figures is italicized because, having come awake at 2:30 and being unsuccessful at returning to sleep, I had lots of time to read more Pym and to think about words. At about 4:30 I became awash in the charm of "it figures" -- the term is arithmetical, or it is philosophical, or it is casual, or it is as precise as a puzzle.]