I was at the non-Brain part of Research and it was seen as Google Brain is the "cool", pure research one, dealing with some future abstract AI and not caring for the products, feasibility, or even if the research "could" be made practical any day.
Deepmind was an "extreme" version of it, with some animosities and politics between the two, which I didn't follow too closely. There were attempts at making Deepmind useful, called "Deepmind for Google", but the people there were... clueless. Though one really cool thing came out of it (XManager).
(I was at a closer to the product part, "Perception", which I loved. And still got to publish, explore, pursue my own research goals, etc.)