Following the panel, a C&W spokeswoman told GlobeSt.com that Manhattan's commercial vacancy rates, including sublease space, were 8.9% in 2001, 11% in 2004 and 8% in 2008. However, the industry consensus is that vacancies could exceed 10% before the current year is done.

Panelists acknowledged that the credit crisis is what they find most "disquieting," saying it is "killing" them for now. But they predicted that once that eases, the market will once again become more liquid.

"We are still in ratcheting-down phase," said Freedman. He added that once the market starts skidding along the bottom, people won't be deferring decisions like the earlier Park Avenue hypothetical question. At that point, herd mentality takes over and "you start to establish clusters of transactions, or critical mass and demand feeds itself." This will lead to what Freedman called "tilt" transactions.

But for now, with mass layoffs, downsizing and other uncertainties raising their heads across the market, questions arose related to current realities like a rise in business for sublease agents. Marek set up a scenario where a sublease agent for a tenant is paying $94 per square foot for 15,000 square feet in a great building. But there is space on the market at $89 per square foot. Then suddenly, an offer comes in at $50 per square foot. "How you would handle the situation?" Marek asked the panel.

"Take it and run," said one panelist, evoking laughter in the audience. However, on a more serious note, Rhulen said, "in this market, the word 'no' cannot be in your vocabulary if you are a sublease agent."

Rhulen said she was surprised by "how low some landlords are willing to go." She added, "Every month that goes by is downtime in this market. It's not like you've got a number two or three lined up behind them."

Rhulen said landlords were being flexible with short-term renewals. In common with other panelists, she said she's seen turn-keying, deals in which the 12th month is free and pre-building and more variation on terms.

She said that she'd done a five year renewal, then the broker called back and said that the tenant only wanted to stay for a year, so would she be willing to give the right to renew for four years. "The landlord said sure, he was getting fair market value, saying, 'get the deal done,'" Rhulen told the group. "Any landlord who is aggressive and has some cash on hand is also doing pre-building."

Still, Preate noted, it's probably not fair to say that a trend had been established based on the landlord variation or concession stories, since there is not enough of a sampling of deals to make a determination. And panelists agreed that despite any temptation to do so during economically challenged times, rent reduction was a better option than any compromising of security. In fact, they said they would forgo rent for more security.

Moving onto short-term leasing, a few of the panelist agreed that six months of occupancy was far better than six months of vacancy. They compared empty space in a commercial building to planes that fly from one city to the next with empty seats.

But with subleasing comes risks, both for landlords and tenants. One nightmare scenario is having a subtenant go bankrupt, which can cause issues with a building. In fact, as the panel noted, a bankruptcy court can exercise "jurisdiction" over a property.

Another cautionary note that Friedman sounded: "Make sure tenants keep with the dignity and character of a building. I've seen quality buildings schlocked up in the past." That in turn exerts a downward push on the long-term asset value of the building.

Looking at the long term, Freedman advised, "If you start rejiggering rents out another three years, you are going to have, structurally, the most massive demand in the history of this city on the other side. This is going to accelerate market recovery."