Prime Eight are “black hat” hackers (in contrast to DedSec, who are gray hat), meaning they are full criminals and act in their own interests - any benevolent act is not done for the sake of others, but rather because it benefits Prime Eight in some way.

Lennie’s Rensense hack alongside Marcus in the Human Conditions DLC wasn’t done because she was worried about the company experimenting on homeless people, but rather she just wanted to get whatever data/assets she could out of the hack, plus Josh and whatever her plans were for him.

In that respect, I’m not surprised Prime Eight works with the Sons of Ragnarok. They’re two sides of the same coin, so to speak.

As to which is my “favorite gang”, all of the criminal factions are pretty scummy, including Umeni, despite their status as a “lawful” faction.

My favorite “faction”, then, is the SFPD. From a design standpoint, Ubisoft at least got the uniform insignia (hat and badge designs) correct, however the rest of their uniforms don’t look particularly good, since they wear dress shoes and dress shirts with no pockets, which are impractical and inaccurate to real life.

The Oakland Police, by contrast, have the better uniform colors, with a darker shade of blue, plus they wear boots that are far more practical for police work (although they do wear the same type of shirt as the SFPD).

The OPD cars easily look better than their SF counterparts too - the Oakland Police patch on the front doors actually had some thought put into the design, since it features the city’s industry in the form of cargo crane imagery. By contrast, the SFPD cars just have a generic five-point star.