My initial impressions reading the buffs: that is objectively a 4.3% increase to theoretical GCD rotation, and empirically based on Susano EX numbers that means yeah about 2-3% overall. That's... comparable with patch 2.45.
My initial impression after taking a few attempts at a dummy: This does buy you a little time for eyes falling off in a raid, but the part that strikes me immediately is that it seems you're no longer supposed to hold that itchy Geirskogul finger forever just to get BfB and enough seconds on BotD to get 3 Nastronds; the timer part should happen more naturally.
That's kind of the logic I've been going by as a casual... at least when it was 6y, if a healer wants to stand so close to the (ahem) spear-wielding liability that they could get the buff, they deserve it whether they want it or not.