Are budget third-party primes from Viltrox, Meike, and Brightin Star worth it?

Reviewer consensus is split by brand. Viltrox in particular gets strong reviews from specialist communities for autofocus performance and sharpness at very low prices. Manual-focus ultra-fast lenses from Brightin Star are praised for the price-to-aperture ratio but flagged by reviewers for soft wide-open performance and weak contrast at f/0.95.