If you mix or master music, this is a very useful piece of gear. Arguably, you could get all the features from the clarity out of free (or cheaper) plugins, but it's really nice to have a dedicated screen for continuous analysis without loading your computer. I use it with the ADAT connection, so the Clarity analyses whatever comes out from my interface (including Spotify or Youtube), which is quite insightful for reference tracks. I'd recommend this if you have some spare cash, but I wouldn't say it is a must.
The only thing I wish it was better would be making the spectrum analyzer full screen with some more bands, which I assume shouldn't be impossible via software update.