I considered it very enjoyable and read it after I finished the original manga. You can just laugh at the absurdity and stupidity of Motoyasu's actions. It especially amused me how others in the story reacted to Motoyasu. As for the story itself, it offers some interesting lore and information we otherwise did not get in the original, but it does not offer much as far as substance is concerned. We learn more about Motoyasu's state of mind after some of those events in Shield Hero and see how he handles things "differently," in order to fulfill his obsessions. It is a simple comedy spin-off.
Basically, read if you want more Shield Hero and you would be pleased with following a comedic adventure with Motoyasu doing dumb things.
