Several New York Islanders flags hung from the windows of bars and restaurants on Fifth Avenue one recent fall afternoon, the imposing, rust-colored arena looming in the background, as the neighborhood readied itself for the start of the hockey season.

Barclays Center has only been home to the previously Long Island-based hockey team for a season, but in the four years since the arena opened its doors residents and businesses alike have grappled with a changing neighborhood dynamic, crowds, fear of rising rents, and what many have categorized as a balancing act between the definite benefits of increased business opportunities and the commercialization of brownstone Brooklyn.

“They’re seeing more Islanders fans using the bars and restaurants as kind of a home base,” said Mark Caserta, the executive director for the Park Slope Fifth Ave. Business Improvement District. “The fans [at Nassau Coliseum] were never used to having bars and restaurants nearby. Now it’s a little bit more like going to Madison Square Garden.”

New York’s “other” hockey team has actually provided more business for the area than concerts or basketball games, Caserta and several local business owners said.

But converting the stadium into a hockey arena was not without its controversy, with several seats offering obstructed views. Barclays Center, built with the Brooklyn Nets in mind (who have played at the arena since it opened in Sept. 2012) is the second-smallest NHL arena with a capacity of 15,795, including about 1,500 obstructed-view seats.

The team does have an opt-out clause in its agreement, meaning they would be able to leave the Brooklyn arena after three seasons.

This would be bad news for some businesses who are looking forward to the boost from another hockey season.

Gennaro Chimienti, 48, floor manager of Patsy’s Pizzeria on Dean Street, said Islanders fans show up in droves before games, more than any other event. The restaurant has been open for over a year.

“It is very busy,” said Chimienti. “It’s a lot of energy, it’s a lot of fun ... A lot of beer flowing, a lot of wine flowing.”

Michael McMahon, who owns McMahon’s Public House on Fifth Avenue, said Islanders fans tend to show up two or three hours before the games.

“They’re great fans and they’re a great crowd that comes around. They’re great sports fans. They seem to just come to enjoy themselves,” he said. “For business they’re fantastic.”

Mandy Gutman, a spokeswoman for the Barclays Center, pointed to a survey conducted by the North Flatbush Business Improvement District that found some local shops reported up to a 20% increase in business from Islanders fans through May 2016.

“We’re proud of Barclays Center’s positive impact on the surrounding neighborhood,” Gutman said in an email.

But the boost from hockey fans — and those attending all Barclays events, for that matter — has been a trade-off for some, including Geronimo Diaz, one of the managers of decades-old Yayo’s Latin Cuisine on Fifth Avenue.

The crowds and lack of parking from the arena over the years, he said, have started to drive out his regulars.

“It’s a little better. Not much, not what we expected,” Diaz said about the increase in customers thanks to the Islanders. “[Regulars] know when something is going on at Barclays; they don’t come here. Only the people who come to the show and you cannot survive only on those people.”

Overhead costs are another concern for businesses in the area, an issue that hasn’t even fully come to fruition yet. Diaz said the restaurant has about three years before its lease is up, which will force them to renegotiate the rent.

Several chain retailers and restaurants have opened in the area, including Shake Shack and clothing store True Religion.

Caserta said it could be “a number of years” before the full impact of potential rising rents is felt, but he didn’t think attracting big-box retailers would affect Fifth Avenue as much as surrounding blocks because the storefronts are fairly small.

“There are still people who have leases down there,” he said. “So the question is when their leases are up, what happens.”

Edwin Asencio, 24, one of the managers of Kith, a sneaker and apparel store on Flatbush Avenue, said concerts have been a real draw for the store, which he said has been open for about five years.

“The crowd for the Barclays is definitely what caters to the store right now,” said Asencio, who said when there is an event he receives about 20 extra customers. “It’s so close, it’s two attractions you can stop at.”

Brooklyn Chamber of Commerce President Carlo A. Scissura said business owners in neighborhoods as far as Brooklyn Heights have said they get customers from the arena.

“The bottom line is Barclays Center has been incredibly great for Brooklyn. We now have an entertainment venue that has almost every night of the year booked,” Scissura said. “If that arena were not there, a lot of these places would not have the business they have. There are people there all the time.”

That is true for Giuseppe Piazzolla, who opened his Italian restaurant Broccolino in May 2013. Piazzolla said he tends to get more local customers than eventgoers, but his small restaurant is rarely empty.

“We are never slow because we have people from the event and then after we have locals,” he said, adding of season ticket holders: “They come every game. We call them like locals because they always come. It’s a kind of tradition.”

Many Park Slope residents were up in arms when the arena was first announced, worried about everything from crowds and noise to available parking spaces. Four years later, these issues are still major concerns, but several residents said it hasn’t been quite as bad as they expected.

“It’s not super desirable parking in this area, but it hasn’t changed,” said Peter Jehl, 33, who owns an indoor rock climbing business close to the arena. “It’s never going to be Madison Square Garden.”

Chris Edgemon, 33, moved to the neighborhood just before the Barclays Center opened and has seen the area transform over the years.

“It feels like a neighborhood in transition,” said Edgemon, an architecture student. “The thing I miss most is the character of the businesses is oriented toward [Barclays Center attendees] as opposed to oriented toward the neighborhood.”