You can up with your own conclusion on what it means when an independent organization in the FBI says it is "minimally corroborated." And the director states that is "Salacious and unverified."
I would say that makes anything in it questionable, especially as evidence. If your a proven liar are you going to be a good witness in court? Probably not.
This is the transcript on what Comey said:
BURR: In the public domain is this question of the “Steele dossier,” a document that has been around out in for over a year. I’m not sure when the FBI first took possession of it, but the media had it before you had it and we had it. At the time of your departure from the FBI,
was the FBI able to confirm any criminal allegations contained in the Steele document?
COMEY: Mr. Chairman, I don’t think that’s a question I can answer in an open setting because it goes into the details of the investigation.
. . . .
BURR: So if you’ve got a 36-page document of specific claims that are out there, the FBI would have to for counter intelligence reasons, try to verify anything that might be claimed in there, one, and probably first and foremost, is the counterintelligence concerns that we have about blackmail. Would that be an accurate statement?
COMEY: Yes. If the FBI receives a credible allegation that there is some effort to co-opt, coerce, direct, employee covertly an American on behalf of the foreign power, that’s the basis on which a counterintelligence investigation is opened.
BURR: And when you read the dossier, what was your reaction, given that it was 100% directed at the president-elect?
COMEY: Not a question I can answer in open setting, Mr. Chairman.
. . . .
KING: In regard to him being personally under investigation, does that mean that the dossier is not being reviewed or investigated or followed up on in any way?
COMEY: I obviously can’t comment either way. I talk in an open setting about the investigation as it was when I was head of the FBI. It is Bob Mueller’s responsibility now. I don’t know.
SEN. SUSAN COLLINS: Thank you, Mr. Chairman. Mr. Comey, let me begin by thanking you for your voluntary compliance with our request to appear before this committee and assist us in this very important investigation. I want first to ask you about your conversations with the president, three conversations in which you told him that he was not under investigation. The first was during your January 6th meeting, according to your testimony, in which it appears that you actually volunteered that assurance. Is that correct?
COMEY: That’s correct.
COLLINS: Did you limit that statement to counterintelligence invest — investigations, or were you talking about any FBI investigation?
COMEY: I didn’t use the term counterintelligence. I was briefing him about salacious and unverified material. It was in a context of that that he had a strong and defensive reaction about that not being true. My reading of it was it was important for me to assure him we were not person investigating him.
COMEY: The president called me I believe shortly before he was inaugurated as a follow-up to our conversation, private conversation on January the 6th. He just wanted to reiterate his rejection of that allegation and talk about—- he’d thought about it more. And why he thought it wasn’t true. The verified — unverified and salacious parts.