Enjoyable short stories, but not quite riveting or deeply involving. Robinson originally wrote these stories as a sort of serial for Analog magazine, and as a group, they show that heritage. Part of what works for them is the mood, a positive, friendly, "we welcome all" vibe with a little bit of accommodating wierdness. However, story to story becomes repetitive if attempted in one sitting.Where Callahan's stands apart is it's focus on struggling with the problems of existence and meaning, and humanity, and the great focus the bar clientele have on empathizing with each other. This is Cheers with puns instead of sarcastic put-downs. Be warned, Callahan's clientele truly love puns, and they will edge into the most serious of stories. Xanth ain't got nothing on Callahan's.Mostly stories aren't explicitly sci-fi, being set in an modern anytime New York bar but instead play with sci-fi concepts like time travel, lurking aliens, and humans with extra abilities. Never fear, all problems can be solved with some creativity and thought. And most likely, bad puns.