If pressed I prefer jewel cases, the disc does not touch any surface and that's for me the most important feature. And all the printed material is protected. Indeed they break by just looking at them and removing and placing back a thick booklet can be a pain. And if you keep some with the center spline broken there's a significant risk that the disc will fall to the ground next time you open the case. But in any case they are easy to replace when they break (you just have to pay attention if the original case had the disc holder transparent with the back cover printed on the inner side, not replace it by a case with black disc holder or you loose the sight of the inner print. Although transparent holder splines seem to break easier than black plastic ones).

Standard size and "opening mechanism" is also an advantage. My storage shelves at home are high enough so it's no problem but for example in the car, different sizes can be a problem, and the CDs are handled and stored less carefully so digipacks can more easily get damaged in the car, and if you want to change the CD while driving, having to deal with different methods to remove the disc from the pack can be annoying.