Did not appreciate "Overtime." The humor was certainly there, but I am not a student of Medieval history, and the legend of Blondel was a complete unknown to me. As a character he was tolerable enough, but not particularly interesting. His sidekick, a classic "permanently confused disinterested bystander" of the "Arthur Dent" genus was simply annoying. Unable to emotionally connect with any of the characters, and finding the plot circuitous at best, I had a lot of trouble wanting to finish the book - although I eventually did. Two stars for this story.
"Grailblazers" is considerably better, IMHO. Somehow tying together everything from Atlantis to Santa Claus in with the (not very interesting) grail, it did so in a consistently humorous manner. The main characters, especially Bedevere, Boamund, and Toenail, were actually endearing at some level. Nothing in the least profound about it, but enjoyable from start to finish. Three stars for Grailblazers.