I found this much more satisfying than Handmaid's Tale, although to be fair it must have been more than 25 years I read the printed page. After watching the DVD from KCL as a refresher, now I finished Testaments. For me it was a steady read, even at 3 a.m. when I couldn't sleep. I don't consider this science fiction anymore than Blade Runner could happen. The future remains ... the future.
By Chapter 29 it came together for me, as I often have trouble keeping the non chronological texts confusing, unless I know the subject well. This writing makes so many references to time periods I know and had to laugh out loud at Shafley Cafe reference. Atwood was wonderful in her word usage, a dictionary often proved useful. Dithery... didn't know this is a root word for once so frequently used.
I liked the suspense, the use of realistic imagery, the personal 'journals' method to deliver background. I'm left with "In the end, how much of belief comes from longing." A thought that may come to one sooner later in a lifetime, it's a matter of reflection and consideration that comes with age. So, discard or contemplate various beliefs.