I can’t find videos of these hearings but journos in the room said they were pretty wishy-washy.
Joseph Jerome wrote a good pre-game article on Slate. Jerome works for the Privacy & Data Project at the Center for Democracy & Technology, and it is filled with good links.
John Thune (R-S.D.) published this speech the day of. Caveats for cynicism, I was surprised hear a conservative Senator from South Dakota praising the GDPR.
Then I found this take–that it’s an end around for a federal law that will supercede the California data protections.