This collection ends with a few really good stories but quite a few are mediocre which drags down my rating of this book.
"Orbituary" and "The Billiard Ball" are the stand out stories in my opinion. Anyone who says Asimov can't write should give these a go and it might change their mind.
Of the stories contained herein, only a few are of the kind that you, as the reader, try to guess "who done it" before it's revealed at the end. Doing so will require quite a deep knowledge of scientific and astronomical facts, that went beyond the limits of my knowledge for sure. Others were more of the kind that the reader knows "who done it" from the outset and then follows how they were found out. Still others explore intriguing scientific discoveries which involve someone being murdered but only the reader knows when to all else it appears like an accident.
A common theme throughout illustrates the politics, rivalry and egotism that the scientific establishment is riddled with (if Asimov is to be believed). He certainly gives the impression that he is very knowledgeable about science and what it's like being a scientist.
Worth reading for the gems but there's a few duffers to be glossed over (although a better knowledge of the science involved might improve their reading).