CHICAGO -- ( TheStreet) -- A year after it entered commercial service, the Boeing ( BA) 787 is starting to fulfill its promise, but some question just how much promise it has. Of course, carriers that fly the aircraft, including United ( UAL), which flew its first 787 flight on Sunday, are pleased. In fact, Gerry Laderman, United senior vice president, said investors in the equipment trust certificates issued to finance aircraft purchases have been willing to accept lower interest rates when 787s serve as collateral. Additionally, "We have a competitive advantage being the first in North America" to fly the 787, Laderman said Sunday, in an interview aboard the inaugural intra-U.S. flight. " American ( AAMRQ.PK) is three years behind us, at least." He said passengers making connections to international flights are likely to seek out the 787. But stock market investors do not seem overly excited. Analysts estimate that Boeing will have to sell 1,100 jets before it makes a profit, and aviation consultant Richard Aboulafia maintained that while the 787 is a nice airplane it is hardly transformational despite all of the hoopla that surrounds it. "A lot of people have thought about the aircraft in terms of a revolution," Aboulafia said. "It's not that." So far, Boeing has taken orders for 838 aircraft and delivered 33. On Thursday, Nov. 1, a year after taking delivery of the first 787, Japanese carrier ANA said it is flying 16 of them. "ANA is delighted with the performance of the 787s in its fleet over the course of the last year," said ANA CEO Shinichiro Ito, in a prepared statement. ANA said the aircraft's fuel efficiency exceeds initial estimates: The savings in fuel costs are 21%, compared with an estimate of 20%. It said passengers prefer the airplane, with 40% saying they specifically selected the 787. Another indication of the 787's promise came late last month, when Singapore Airlines said it will sell five A340-500s back to Airbus, and would order five A380s and 20 A350s. The A350 and the 787 are similar in that both are smaller, long-range aircraft, and aviation analyst George Hamlin said the transaction is an indication that the 787 "has proved its point.