The core idea of a programmer and a mecha otaku being reborn into a fantasy world, only to find it has magical mecha, and throwing himself into the subject with all the seriousness of an otaku who can finally get close to his obsession in real life, is pretty fun, and the enthusiasm of the main character really carries the reader along... But I find that when one character is the best at fighting, and magic, and inventing, and tactics, and is extremely handsome, and a natural leader, and utterly fearless, and and and, and that's all before we even get to his main specialty... it actively takes away from the story being interesting. Unless you play it up for humour, I guess, and even then it might get old fast. And this book plays it completely straight.