Nah, they're great. One just has to know the limitations. Books and bungee cords don't go together, that's true. The books are so flat and smooth, it's rather difficult to keep them in place with bungees only. Probably possible, but takes some figuring out and testing...

Panniers are even greater though. Their main disadvantage is that they are bloody expensive! If you can afford one - luky you; if not - wire baskets and milk crates rule!