I would say that you've got three main classes of vertical cookers: Cabinet offsets, Cabinet directs, and vertical directs. Vertical directs includes UDS, PBC, WSM, BGE, and all sorts of things in between. There are exceptions, such as removing the water pan in a cabinet direct smoker, and some vertical directs also have baffle/barrier options. In general, I don't think that one is "better" than the others at any thing, but what I call vertical directs tend to have more limmited space, limmitted means of accessing "lower" racks, and limmited abillity to add more fuel. On the flip side, they are often very affordable fuel consious, and set/forget.
dmp