My assumption is they vetted them themselves. We ultimately made the selection, but with input from them and the other sources named above.
The integrator for this project is a sub of the electrical contractor, but they are a certified dealer and installer based out of another part of the state. They are waiting on the A/E firm (the A/V consultant they contracted with, actually) to come up with a solution. I believe everyone, including the A/V consultant, the sub, and us initially thought it would be a plug-and-play process.
After the selection was made, I had our local integrator convert a few of the legacy cameras outside the scope of the project. They use a different PTZ protocol, and that went fine . . . after adding code mergers and code translators in addition to the Avigilon coax-to-Ethernet encoder. The remaining cameras use a different proprietary protocol and/or are already IP, but I am told by the local integrator (different than the integrator for the project) that the conversion process will be essentially the same. They know how to do it. Problem is I can't get the A/V, A/E, or sub to talk to their competitor. But that's a whole other story, and slightly off topic from this thread.
Bottom line - our legacy cameras are not plug and play with ACC. We were initially led to believe they would be.
I will say, though, that even if we had been told up front that additional, and somewhat expensive, code translators and mergers would be required, we probably still would have chosen Avigilon from the choices we were presented with. We just wouldn't be as frustrated as we are because a marketing claim turned out not to be true.
After all, aren't all marketing claims - especially if they are on the internet - supposed to be true?