I think it is important to note that, while metal halide lamps do indeed have the advantages outlined in the article, they are still essentially improved mercury vapour lamps. These improvements are not particularly novel, having first been described in a US patent issued to Steinmetz in 1912. Indeed, a typical metal halide bulb used for fluorescence microscopy contains about 3 times as much mercury as a 100 W mercury short arc bulb used for the same application.  Several companies, including the one that I work for, now offer light sources for microscopy that are completely mercury-free and do not utilize bulb consumables.  The spectral content and power outputs of these modern solid-state light sources is at least equivalent to and in most cases superior to that of mercury and metal halide lamps.