The edition I read was the "Omnibus" version, including the "Smoke Ring" and a concluding short story right after that.
A truly outside-the-box bit of world building: how about a zero-G atmosphere without a planet under one's feet, living in open-air orbital "trees"? Re-imagine your entire ecosystem without gravity. I found the idea very engaging. The story-telling was also quite first-rate. Marked down one star because I think the book could have benefited from being longer, with more character-building. I felt like I was skimming over the surface of the cast of characters, getting to know all of them a little, none of them very well. While not a home run, this book was very memorable.