A few threads which I commented on which explain how the espionage happened, what kinds of information was delivered, and what the Soviets did with it (and what other things they did):

• How did the Soviet Union manage to acquire atomic bomb technology?

• What specifically did the Rosenbergs give to the Soviets?

• If the Americans secretly invented the atomic bomb, how did Russia get their hands on the technology so soon after it's invention?

• Did the Rosenbergs commit espionage or was it an unfair trial during a period of fear?

The short answer: they did use the espionage information for some top-level decision-making, but they were never reliant on it. They almost entirely re-confirmed every bit of it, and the Americans said something wouldn't work, they confirmed whether that was true or not. In other words, they didn't use it to take many shortcuts, because they didn't entirely trust it. But they did use it as a guide and a "check" on their own work. And they did explicitly model their first bomb test after the first American one, because the head of their program (Beria) wanted a guaranteed success.