themed anthologies as a literary form. I bought two such anthologies only because each included one installment in different series by SM Stirling and I have not read every other item in either anthology. Themed stories by several authors seem samey if they stay on theme but senseless if they stray off theme.
My Christmas presents include a small, slim volume containing a 58 page story by Neil Gaiman, a sequel to his TV series and novel, Neverwhere. This story had originally appeared in an anthology, where I had not heard of it. I prefer to receive it in this form. Minor coincidence: a new character is called "Peregrine" and I have just reread Poul Anderson's The Peregrine.
Anderson's three Man-Kzin Wars stories should be collected in a single volume which would then form one volume both of Poul Anderson's Complete Works and of the Man-Kzin Wars period of Larry Niven's Known Space future history. The three stories are consecutive, therefore need not be interspersed with installments by other contributors. They also contain major speculative fiction by Anderson.