If we're not counting the books about Miles' mom, this is the real start of the Vorkosigan Saga. It's an excellent introduction to Miles, one of the most memorable fictional characters I have ever encountered. This is the story of how Miles, crippled as he is, just can not be contained. Everyone, including the reader, gets swept up in his wake.
Forward Momentum! <- I want that on a T-shirt.
Thoroughly enjoyed the latest reread, even if it was at least the 4th one.