The last third should have been a short epilogue or a full sequel. It's too much of a pivot in terms of tone and focus, and feels incongruous and mismatched with the first two sections (which are excellent). He clearly had a bunch of ideas that didn't fit into the main body of the work and grafted them on anyway; it wasn't bad, it just didn't fit.

The comparison would be Orson Scott Card writing Ender's Game to set up the universe of Speaker for the Dead, but instead making Speaker for the Dead a third of its size and calling it the last few chapters of Ender's Game. They should just be different works in the same setting.

For me I skipped the 4th third. Like I always do.

For me, it was the middle third I skipped. Seemed to drag forever.

Same, I enjoyed that book beginning to end.