Find my post in another thread about my roof boxes. I won't repeat the whole thing, but I have an old Packasport fiberglass box which is heavy and sturdy, but not that big. We bought a slightly used Yakima SkyBox Pro 21 last year which exploded driving home from skiing this winter. However, it appears that this may have been due to (1) me storing it in my garage resting on its end, which can deform the shape of the box, and (2) the old latch and hinge design, which was poor. The new ones are better, and I will probably buy another one this summer (and hang it properly in my garage). I don't think the Thule and Yakima boxes are very different.
If you don't mind a heavy, smaller, more expensive box, get a Packasport!
Neither box interferes with the rear hatch or the sat/nav.