Not necessarily. I think you’ll commonly find both. Also, I think the actually chip or R-2R isn’t the important part, but the implementation of it.
In short, when I dipped my toes in multibit, I felt a large improvement in sound stage, dynamics, bass slam, and timbre. The instruments sound a lot closer to its sound and voices sound more like voices.
I made a longer write up here, in case you were more curious and have some time to kill.