I would say that Planet of Judgment
was the better of the two novels released at the time (the other being Marshak & Culbreath's The Price of the Phoenix
), but only about average for the Bantam era.
World Without End
fell into the period when Bantam had fallen into a rut, and literally every other novel was garbage on the theme of "Kirk leads a landing party on a visit to a primitive society that turns out to be something other than what it seems," and while it was arguably the best of the four novels on that theme, it wasn't especially good, and wasn't especially true to the Star Trek milieu.
Alan Dean Foster's Star Trek Log
series led me to his The Tar-Aiym Krang
, and his other Flinx novels, and his other Humanx Commonwealth novels, and most of his other works, and David Gerrold's script of "The Trouble with Tribbles," and his book about the episode's genesis, production, and aftermath, led me to When HARLIE Was One.
But Haldeman's Star Trek novels did not impart to me any interest in seeking out his other works.