It is brilliant. there are dull passages, where nothing much happens other than playing cards, but it's a depiction of the strange uneven pace of trench warfare, so stick with it.
Well worth digging out a copy of the sequel, The Road Back, which says more about the dislocation of war, as the surviving soldiers try hard to re-integrate into a society in turmoil, among people who have no conception of what they have just been through to defend a state that has crumbled in their absence.
Three Comrades also covers much the same ground, but gives a slightly different aspect.
If you like All Quiet..., it's also worth trying to find Under Fire by Henri Barbusse. I think it should be compulsory reading for all those comfy Yanks who propagate the myth of the French as cowardly. Gripping.