It's a fairly quick read as far as board review books go. Each case is only 2 pages and if you conceptually understand whats going on then you may not have to memorize every single detail in the work-up/management.
The thing that I really liked about crush is that it was divided into sections of chief complaints (e.g. chest pain, SOB, fatigue, abdominal pain). So of the 10 cases under chest pain, you see what the starting work-up should be and then where to fork it and actually dx/treat the specific disease process. But the initial work-up is for the most part the same.
And you're guaranteed to get one case each out of most of the broad chief complaint categories.
uWorld was nice for depth and detail of individual cases but I thought Crush developed a much, much better algorithmic approach to the random unknown case. (which not coincidentally is how EM and a lot of real world medicine is practiced).