Skip it, there are much better seafood restaurants in the city (Oceana, Marea) for a comparable price.
Also if you are looking for DB restaurants I very much prefer townhouse over fishtail.
120 W 49th St, New York, NY 10020
240 Central Park South, New York, NY 10019
We had dinner at Fishtail last year. Our main course was the whole branzino, which I would certainly recommend as it was perfectly prepared and delicious. Everything else we had was excellent, but none of those dishes is on the current menu. However, we had the pastrami salmon, which is one of his signatures, years ago when he was e.c. at the Park Avenue Cafe, and it was very good. We had another of his signatures, the lollipops, at his NJ restaurant. Though they were fun, I wouldn't order them again.
With regard to seating, the bar room, which is long and narrow and has booths, is on the street level. One flight up are two dining rooms and the outdoor terrace. We chose to sit in the back dining room. More elegant decor than the front. We were there at the beginning of May on what happened to be quite a warm day. We considered sitting outside, but because the terrace is small and enclosed around the sides, it was not airy. On a hot day, it's probably unbearable.