I remember an early work of the second relative being a favourite of my parents. I had no idea (without Wikipedia) of the extent of the subsequent oeuvre (and not just in a narrow sense).
A well constructed puzzle, some rather tasty clues, the two types of extra letter generation kept the level of attention up, an interesting theme and the final stage of the endgame did not require endless grid-staring. So I’m with Drxx on this one. Thank you, Skylark.