Great episode. It had a much more emotional impact than the Supergirl season finale. The theory about hostage Iris being HR in disguise proved to be true, but it didn't diminish the tragic loss of life in this case, although Iris was saved.
It was effective emotionally, but it bugged me logistically. If HR was alive long enough to give that poignant farewell speech, then it certainly should've been possible for the Flash to rush him to a hospital and for the doctors to save him. Although, well, maybe you could argue that he was too badly hurt to handle the high accelerations, but that never seems to be an issue in other cases; one assumes that the Speed Force energies surrounding a speedster have an inertia-damping effect.
Something similar also bugged me in the finale. The quakes and lightning and stuff were endangering lives all over the city, but the city's entire superhero contingent was just standing there for several minutes saying their farewells to Barry, instead of trying to help the citizenry. Sure, yeah, his entry into the Speed Force would end the danger, but what about the people being hurt in the meantime?
From Barry's lines to Wally at the end there, I wonder if we'll see Wally graduate to being the Flash next season, rather than Kid Flash. Although that would be awkward when Barry comes back.
I wonder why Savitar Barry continued to have "altered memories" of present events. HR's death should have a created a new timeline that was now separate from Savitar's, so he shouldn't be able to have any more visions.
I guess it's part of the same handwave they used about how it took time for "the paradox to catch up" with Savitar. Logically, he shouldn't exist, but a time remnant has a certain ontological inertia, so it takes time for the universe to eradicate the inconsistency. That clashes with Thawne's instant disappearance when Eddie killed himself at the end of season 1, but it's nicely consistent with Thawne's arc in Legends this year, with Thawne constantly racing through time and never staying in one place long enough for the Black Flash to catch up with him. They even used the same visual effect for Savitar's disintegration that LoT used for Thawne's.
(and BTW - I find it funny no one stated the obvious: That based on the article from 2024 they ALL know Barry will escape the speed force...only to disappear again in 6 years.)
There are also Abra Kadabra's and Savitar's references to "DeVoe" as a future adversary of the Flash, as well as Abra's account of his own years-long rivalry with Barry. Still, the characters know the future can change. Maybe they'll find that the future headline is no longer there in the Time Vault.