This collection of novellas was my introduction to Miles Vorkosigan, and while I suspect that the first book (The Warrior's Apprentice) Might have been a better opening, it did convince me to read every one that our libraries contained, and finally to begin collecting the series.
This collections contains three complete novellas and a, well, best described as sort-of-a-story to connect the three very different events in Miles' career. This wrap-around story is the main reason I gave the collection a mere four stars; it contains a suggestion of a rather scanty plot against Lord Aral Vorkosigan via Miles' more unusual adventures (Or rather, his monetary expenses), which serves no purpose except to perhaps introduce the idea of the imperial Auditors used in the later book Memory (And much better introduced within that book itself). As another reviewer said, the novellas could probably stand alone safely.
As for the three stories themselves, they vary immensely in theme. "The Mountains of Mourning" is a tale of Miles Vorkosigan's early years, and in theory it is a murder mystery, but the emotional impact on both Miles and myself as reader was quite incredible. This is probably the best of the three stories.
Following this, "Labyrinth" is a bit of a surprise; an almost rollicking adventure of Miles as the little "Admiral Naismith". It was grerat fun, but there was very little real emotional impact. It contained another excellent character, but felt to me like it was lacking depth - it was a plot-driven story, and shamelessly so. Having reread it sicne, it is better than my first impression, but the difference between the two stories was a bit of a shock.
The last story, "the Borders of Infinity", combined the two nicely - a rapid-paced adventure with a strong heart and some emotional twisting. Here Lois achieves something amazing in itself - she shows the story from the point-of-view of the one character who *really* knows everything that's going on, yet doesn't give away her own plot in so doing.
All in all, this hooked me on the little hyperactive madman; I've sought out every book of hers I can since.