I was pleasantly surprised by my last visit to Akco Lounge. Next to Ho Shim, I always thought it just served up Ho Shim food (which is quite cheap and only so-so) at more expensive prices in nicer digs.
I went for lunch on a Friday with a coworker because it was close. I ordered the Salmon Set - I got 6 pieces of salmon sushi and one salmon roll for $12.95. Fairly reasonable for this neck of the woods in Financial District. As Karen S says, they also have 30% off food from 3pm-7pm, so I can see that as a great deal.
My sushi tasted surprisingly fresh and had a sauce that was quite delicious. It was the type of sauce you would get in spicy tuna or spicy tuna roll - worked really well here. It also came with miso soup and salad - fairly standard issue but no stand-out here.
I was debating about giving it between 3 and 4, but I decided to bump up to 4 stars due to the sauce, the location and decor (swanky dark) and reasonable prices for its location. Service was efficient. I would recommend this place as a decent sushi place for lunch. I would return again.