"Acrylic at its worst can be a garish mess of various transparent colours, glued together roughly or fastened poorly with screw-heads hanging out and cold cathodes everywhere. An LED fan here, a fluorescent something or other there, packed with a rat's nest of cabling.
However, at its best it can be the only case that goes from solid black opaque panel to perfectly translucent window with no visible seam. The reservoir can be built directly into the front panel, creating a "waterfall" look through careful bends. Wires can have clear or opaque channels formed that are fused directly into the shell, hiding the unattractive while flaunting the carefully planned.
Acrylic, my friends, is the only material where a case can be made to be genuinely just two pieces – the base, and some form of entry. It can be crafted to something that no metal, no wood, no anything can make.