I like the "union box" for walls that will have a very thick finish material applied. They have the nails at the very back corners of the box, so you can leave them stick out up to a couple inches, if need be. You can also nail them on from behind, like sticking out of exterior sheathing or shear walls, which is more difficult to do with the typical blue zip box.
Of the very few broken union box ears that I've run across, I think I can safely say that 99% of them had the wrong size screw installed. A #8 screw in the #6 device screw hole will absolutely break it. The other 1% I think were abused between the ruff and finish by other trades.