I like how easy it was to get up & running, both as GUI user or command line interface (CLI) only experience level users can use this product with ease! As of now there isn't anything that really annoys me about blackarch linux; however if you are looking specifically at using Kali in order create custom live CDs/USB's then kali has some issues when creating them from their iso image file(or rather lack thereof).
The support team does all they need too ensure your problem gets solved quickly so don’t be afraid to reach out via IRC channel etc but also feel free ask questions directly through mailing list / forums - we will try our best help solve any issue which may arise during setup process :) This software should have better documentation though not much different than what people already know by heart i guess? Security assessment purposes mainly.