Bluetooth has been pretty useful for me; the only problem I run into is device detection, sometimes, but once the two devices pair, rarely are there further problems in the file transfer process.
Some of the cheap USB hardware are unofficial clones, which get disabled by the official drivers. The clones sometimes work in Linux, but not reliably. It can be really hit and miss.
The transition from ALSA to Pulse never really fully happened and a lot of backend stuff is still dependent on ALSA. If you ever find that you have an audio channel that is just not working for no apparent reason (like audio input), run alsamixer and check if the channel is muted there.
I've found this multiple times on new Ubuntu-derivative installs, and the channel muting in ALSA is not reflected anywhere in the desktop GUI audio settings and can't be adjusted through them, but nothing is technically broken - you just have to raise the volume on that channel via alsamixer. It's a very annoying gotcha.