* The FBI launched their investigation into Russian election interference and the involvement of certain Trump campaign linked people before they ever even heard of the Steele Dossier. So no, they didn't use the dossier to launch an investigation.
* The FBI/DOJ provided REAMS of evidence to justify the Page FISA warrant. Barely any of which came from the dossier.
* The FISA warrant was re-authorized by different judges THREE TIMES because it paid off, and produced valuable intelligence. So I just want to be absolutely clear here, the GOP is super super super super angry that the FBI got this right, snagged valuable intel on an ongoing Russian attack against the US election system, but it implicated someone with an (R) after their name so this is an outrage!
* EVERY single authorizing judge was a Republican appointee. One Reagan, one HW Bush, two W Bush appointees.
* The warrant on Page wasn't even requested or authorized until after he had left the Trump campaign. Not that it would have mattered if he had still been on the campaign given the weight of justifying evidence.
* Every single thing Nunes' memo claimed the DOJ and FBI witheld from the FISA court, was not withheld at all. Schiff went so far as to directly quote the section of the FISA application where the court is told everything Nunes and his people tried to claim wasn't told to them. So they were either stunningly incompetent, or lying, when they made that claim in their memo.
* In order to sell those lies to the public Nunes flat out mishandled classified intelligence. He was in no way authorized to release anything in his memo to the House as a whole, he did it anyway. Then he sought retroactive declassification from the President.
* Fun tidbit. The FBI has verified a bunch of dossier details. Trump didn't want us to know which so he redacted almost the entire section listing what had been corroborated. Even though the dossier is public.

*The Nunes memo falsely claimed the FBI used a yahoo news article as corroboration of Steele's dossier. They did not. The news article was cited to call attention to the court that Page was issuing public denials of things (denials contained in said article) that the FBI knew he had done. It was presented as further background Page was hiding things.
Etc....
Basically, nothing of Nunes' memo is left but a smoldering crater after going through this, even with the redactions. There was nothing remotely resembling any abuses of FISA. Procedures were followed exactly properly, and produced results as intended.
Nunes's memo was 100% a political hit job against the DOJ and FBI trying to derail the Trump investigation, and nothing else.