Those credit unions are quick to sing Fiserv's praises.

For the Carson City, Nev.-based, $457 million Greater Nevada Credit Union, the Fiserv acquisition of DNA was an answer to a prayer, said CEO Wally Murray.

The credit union was on Fiserv's aged CUBE system and was looking for new core. Its first choice had been OSI's DNA, but Murray said he could not abide the company's high debt load. “DNA was a proven performer, it might have been our first choice,” he said.

He elaborated that Greater Nevada had closely eyeballed Acumen, DNA and Symitar, eventually ruling out Symitar.

“It just wasn't a good fit for us. We felt it was older technology,” Murray said.

Acumen and DNA also presented issues but with Fiserv's January announcements, everything fell into place and Murray signed on the dotted line for Fiserv's DNA.

At Randolph Brooks Federal Credit Union, a $5.5 billion institution based in Live Oak, Texas, the situation was different, but also very similar. It had announced it was converting to Acumen after 30 years on a home-brewed system. Then Fiserv pulled the plug on Acumen.

Randolph Brooks Vice President of Electronic Services Mary O'Rourke said in her mind, it's all working out for the better. She said when the news broke about Acumen, Randolph Brooks' only time investment had been in preparing its data for a conversion, work that would have been needed regardless.

As it further happened, Randolph Brooks also had been a fan of DNA but also had been put off by Open Solutions' balance sheet. Fiserv's acquisition put DNA back in the picture, and the institution is on schedule to undergo the conversion in third quarter 2014.

“Now that DNA is part of Fiserv, we're getting everything we wanted: a proven, modern technology platform in DNA, the financial stability and market leadership of Fiserv, access to a vast array of integrated, best-of-breed solutions and the ability to customize our own technology with DNAcreator,” she said.

O'Rourke said Randolph Brooks, which has a technical staff of nearly 10 working on its core, hopes its team will create apps that it can sell in DNA's online apps store.

“We perhaps can recoup part of our costs,” she said.

Next Page: Third Route for Affinity FCU

John Fenton, CEO of $2.2 billion Affinity Federal Credit Union in Basking Ridge, N.J., adopted DNA via a third route.

He had decided Affinity needed to upgrade to a new core after 27 years on a Fiserv core, and in early 2012 he settled Open Solutions' DNA, in part because he had doubts about Acumen.

But as it turned out, the Fiserv purchase occurred during his the conversion, so Affinity completed the conversion as a Fiserv customer.

“We have always had a good relationship with Fiserv and we are glad they spent close to a billion dollars to take Open Solutions/DNA out of debt. The two immediate advantages are that Fiserv has added resources to DNA that has made them more responsive to our needs, and they will now integrate the front end of Acumen into DNA, which means we get the best of both worlds,” Fenton said.

In an interview, Mark Sievewright, president of the Credit Union Solutions group at Fiserv, stressed that there would be more announcements of DNA signings, probably in the next four to six weeks. He said Fiserv's ownership has addressed the balance sheet question.

He also said that Fiserv has increased the investment in providing service for DNA clients.

All in, per Fiserv's numbers, at the time of the DNA acquisition, there were two credit unions live on Acumen and another 10 in the process of converting.

Now, three institutions in that group have announced they are moving to DNA: $1.4 billion Navigant in Smithfield, R.I., $1.89 billion MIDFLORIDA Credit Union in Lakeland, Fla. and Randolph Brooks.

“We will surprise some people,” he said.

Add it up and where does the updated scorecard leave Fiserv?

Brad Smith, CEO of Austin, Texas-based technology consulting firm Abound Resources, said, “Fiserv's reputation was damaged in the larger credit union space—Acumen was a black eye—but they remain the 800-pound gorilla. I don't think it will cause lasting damage.”

He added that Fiserv worked aggressively to smooth ruffled feathers.

“I don't think they have this fully buttoned up but they are close,” he said.

At Cornerstone Advisors in Scottsdale, Ariz., Research Director Scott Hodgins said the real questions are not about the handful of institutions that had signed with Acumen, but rather, the ones who chose to wait out the maturing of Acumen.

“The bigger question is what will happen to the credit unions that were waiting for Acumen,” he said. “They had confidence. This made a lot of them look really bad.”

Sam Kilmer, senior director at Cornerstone Advisors, said that Fiserv's acquisition of DNA had answered questions credit unions had about financial stability, but added there are now questions about how well Fiserv will service DNA.

Despite the questions, Fiserv's 2,300 core clients represent a significant lead over competitors.