Was this a Good day for Trump or for Comey?
What I've seen transpire in the Senate and news today doesn't militate for my considering it as a day meriting, with regard to either man, overly simplistic qualitative assessments on the order of "good" and "bad." Comey said answered questions he was asked and shared, to the extent he could, discussed the nature of his interactions and thinking about various matters pertaining to the FBI, the "Russia"/Flynn investigation, the POTUS and assorted members of his staff.
Legally, Trump should not be legally damaged.
I'd have been shocked were anything that legally damaging disclosed in the public Senate briefing. Were that to have happened, it'd have required that Comey in open Congressional testimony "leak" information about an ongoing investigation.
You'll surely have noted that Comey did tell Trump that Trump was not the subject of an investigation. If you listened carefully and are somewhat aware of how the law works, you'll also have noted that Comey did not attest to whether, as a consequence of his actions to squelch or end the Flynn and "Russia" investigation, he may, as part of the special counsel's examination, now be the subject of an or a part of an investigation. He clearly cannot comment on that because he is unemployed.
Legally, comey should be fine. Even the "leak" is not, by definition a "leak" because it was not a government document that was released by his friend.
Are you referring to Comey's notes? The notes are government property -- he wrote them pursuant to government-business interactions he, as FBI Director, had with the POTUS -- but not exclusively so. Moreover, they almost certainly (given that Comey provided them to a law school professor) don't contain classified information. To the extent the notes do not contain classified information, they surely sooner or later will be released via a FOIA request. Thus, as Comey authored them, he certainly has the right to share descriptive information about them as he sees fit.