I personally have tried FreeBSD and some FreeBSD "distros" on the desktop, and have used *BSD-based stuff as servers/single-purpose machines.
As a desktop system (user-centric use case), you notice how hardware support is sometimes problematic, especially on laptops. I personally had problems with NVIDIA GPUs, already a problem on Linux, being a big problem here as well, and don't mention WiFi (FreeBSD doesn't support 802.11ac and up currently) or Bluetooth. Software-wise, if your applications do not have a *BSD version, well, then you are relying on Linux ports, which for desktop use isn't exactly great.
But, in servers/headless setups, *BSDs are shining, with the most important things running rock-solid, stable and resource-friendly.