I usually like to diffuse direct light mainly so I can have options with all the diffs I can put in front of and really dial it in. Where as using a 4x bounce you only get a 2 or 3 options (hard side/soft side/ reflector). Of course, you can make a bounce light to a book light, but I tend to like to keep a bounce at the ready in case I need a extra return (which I only have one in my arsenal, should probably get another one...).
But it's all about preference! There's no right answer! Try both techniques and see what each setup does. There are certain situations (space/time/gear/etc.) where having direct diffused light is great, but having a bounce source is even greater.