I just finished reading this. I picked it up on a whim in a book sale because it mentioned both the search for a book from medieval times and the character playing a computer game and how the two reflected each other. It was actually a better read than I thought - hey, it isn't science fiction! It was cheap and I thought it would be ok, but in truth it was really well written, and found it hard to put down.
The main character was a bit weak for the investment banker he was supposed to be, but that was really required for the story, and worked pretty well. The computer game was cool and he was entirely useless playing it. It is hard to discuss more without giving away more than I should, but the parallels between his real life and playing the computer game are fun to watch unfold.