It's not some magic bullet. It helps a ton with trying to give names to obfuscated function and variable names, but you have to be intelligent enough to know what the code's actually doing. It probably helps RE teams a lot, but until it can easily run across an entire codebase it's just another tool in the toolbox.
Agreed its can lacking logic till to spell it out, example was this ctf challenge and it just could understand the hash collision till I gave it the full write up [0]
w.r.t codebases I may look at some of the free models (as this gets around the cost problem) and try to feed it prompts as a block of code plus meaningful references to same under the token limit.
I've seen a project for battlefield 3 tho already have the feeling it's a team effort at minimum?