I haven't actually done vDSA myself, but seeing as they appear to have similar drop mechanics, why are there so few complaints (to my knowledge) about how vDSA drops its weapons?
Because apart from the resto they aren't BiS. They also look bad compared to VMA weapons.
Also, it's 4 man. One of the main problems with VMA is the fact not only is the drop rates ridiculous, but it's solo so it's boring af too. For some it's just autopilot mode while doing VMA cause it's so boring, but DSA is different. 4 man, requiring teamwork (albeit the spawns are still the same everytime) and competing for the top scores while farming the loot is more difficult in DSA than VMA.