I can corroborate this. A full size tablet is not always ideal. Display tablets like Cintiqs benefit from larger size because you are drawing 1:1 on a screen. The size allows for comfortable viewing as well as full arm movements on a surface that resembles a drafting table. However, traditional graphics tablets require you to draw on a separate surface while looking up at a monitor. The screen is mapped to the tablet surface, so to move the 10 inches on a 27" monitor to reach a button, you might instead only move your pen tip 1 or 2 inches. In this case, it's often easier to draw using small movements, and zoom in and out as required to work on structure or detail.
Using a large tablet is like using a mouse with the sensitivity turned down. It quickly becomes frustrating having to move your arm around so much to manage the interface, especially when you don't have a direct connection between what you're looking at and touching.
The difference is why someone might use a steno pad or moleskin journal rather than a full-size legal pad.