Boys from Brazil - Did anyone else think the pacing was...off?

Okay, so I finally got around to watching "The Boys from Brazil." I'd heard about it for years, Mengele cloning Hitler, crazy stuff. Gregory Peck is captivating as Mengele. Olivier's performance is really interesting. But honestly, I walked away feeling...disappointed? Maybe it's just me, but the pacing felt super uneven. We spend so much time with Lieberman slowly piecing things together, which is fine, builds suspense and all that, but then the climax just kinda happens. Like, all that buildup for a really rushed series of confrontations? Specifically, the whole "killing the dads" thing felt kinda clunky. There's clearly some mystery at first, but then the movie just spells it out, rather than showing us. It felt like the writers didn't trust us to figure it out on our own? Also, the stuff with the German Shepherd was super odd. Like, that was supposed to be some big indicator these kids were evil Hitlers-in-training, but it came off kinda silly. Maybe it's just the dated effects, or my modern sensibilities. Anyone else pick up on this? Am I missing something? Where are the plot holes??? Also, quick aside: did anyone else think that kid playing the Hitler-clone in the last scene was kinda…weirdly good? Like, unsettlingly good? Seriously gave me the creeps.