Nomad is the best for a first playthrough imho. Mainly because nomads are outsiders to Night City. Story wise it felt right that neither me nor the V I played knew anything about the city or even the situation between gangs and corporations. Through out the story, there are dialogue sections where V seems completely oblivious and sometimes even naive to what is going on around her/him.
When I did choose streetkid, I knew more about the game just like a streetkid would understand the gangs of NC. Though, honestly, streetkid V sometimes felt weird to play. Spends a whole lifetime in NC and looks surprised when certain things are explained that I figured out within an hour.
Corpo V is interesting, better than Streekid V imho. Mostly because the dialogue options that Corpo V gets are more informative.
Thats my take on it, sorry if worded weirdly, but I'm trying not to spoiler the story.