You can find The One Sushi + at 2523 Caldwell Rd NE Ste 1000, Brookhaven, GA 30319 in the Brookhaven Village community. This is part of that large row of buildings along Dresden that has Kaleidoscope on the corner - The One Sushi + is on the back corner as the building forms an elbow along Caldwell Rd. I found it easy to park on the street but your experience may vary - during prime times this area gets quite busy.
I met a few friends at The One for lunch - the double-door entry is on a truncated corner with "The One Sushi +" on a large white sign above the entrance. The interior is industrial-modern which seems to be the norm these days. There are several abstract paintings on the walls, mostly swashes of color. There's a rather expansive bar with back-lit colorful bottles - I liked the atmosphere quite a bit but there are many hard surfaces to expect a high noise level when they get busy. For this lunch it was busy but not too bad.
Prices seem to be fairly typical with a pretty heavy emphasis on alcohol based on the menu. My dining companions like sharable rolls over nigiri so I don't have a lot of opinion on the freshness of the fish. I thought the roll combinations good with a few atypical, most priced in the $11-15 range and fairly large.
The staff was very efficient and accommodating with our questions and requests. The restaurant seemed very clean, which you would expect from a sushi joint. I think we were in-and-out in about an hour.
(also posted to Yelp)