I am new to GotG, so I really enjoyed this origin story. I picked it up after I watched the movie trailer (which was AWESOME). It made me want to read this book. Usually it is the other way around. I go to the movie because I like the books.
Anyway, this book gave me some background on Star-Lord and it made me want to pick up the title for a bit more. Although I saw the main plot line coming, I still enjoyed it, and it helps me to understand the friction between J'son and Star-Lord.
All in all, fun, but not explosive. Enjoyable. I liked it.