Im finishing my first playthrough, and I realized that Vik is the only ripperdoc I have visited in the entire game (beating Fingers and Johnny' shenanigans when he takes control and gets drunk in the Afterlife doesn't count), because why give my money to a stranger when this awesome bud is around?
But that raises a question: all ripperdocs sell the same stuff, or there are cyberware pieces that you can only get by visiting a specific one? Weapon merchants sell different weapon diagrams, after all.