I believe Fravor 100%, and Lazar 80%.
There are a lot of witnesses to the events Fravor talks about and there is no way they are all lying. No sane person wants to jump straight to little green men, but what terrestrial explanation is there for what they saw? I don't know the answer, but if that is the Russians or Chinese I am more afraid than if it is aliens. The craft can go underwater FFS.
With Lazar, it's a bit trickier to sort fact from fiction, but over time his story keeps coming up as true. People said he didn't work there, but it is clear that he did and his descriptions match up perfectly with what others have said of the facilities. He also knew their testing times and took people out to see it, so he had inside knowledge. His more outrageous claims of working on anti-gravity tech are at this point still not verified by anyone else that I know of, but that tech does describe what Fravor and the others have seen.
I havent really read too much about most ufo sightings as when they usually come up in forums with links, everyone says the same thing about Lazar and Schneider - its a trustworthy account. I dont recall coming across Fravor's name though. With what Chup said about the ufo's, I guess we're all talking about what the US Navy is calling the tic tac ufo. Did you know the US Space Rangers fall under the command of the US Navy?
That being said, I did see a tr3b fly over granville island five years ago - fast as fuck and not a noise. I'm of the opinion that these two crafts are terrestial in nature.
If any .gov body is agreeing with UFO stories or sightings, then disclosure should be an eventuality.