I looked at that one about 3 years ago, but was never able to actually see or play with one. It seems like a good design and is a genuine "no moving parts" device, with zero maintenance, and quite accurate if the data sheet is to be believed. It will even detect and measure hail stone fall rate. The force of the impact can be used to calculate the stone mass, in the same way it's used to calculate the volume of falling rain drops.
However, such things come at a price. List price is $2,900. The discounted price is $2,239 which isn't much of an improvement when compared to the instruments that can be thrown together for well under $500 using boards from AdaFruit and other sites supplying hobbyists. Here's some more at the $5,300+ level:
So, who pays $3,000 to $6,000 for a weather station? Anyone that needs reliable weather information in remote or hostile locations, where a service call can be rather expensive. Also, anyone that needs calibrated accuracy, such as military or agricultural weather stations.