I think DODO really suffered with Neal's style of not explaining things to the reader that works well in things like Anathem but less well in a slightly madcap time travel story. I wonder if it would flow better on a second read where you had more info about what was going on, I remember spending a lot of time trying to figure out what was supposed to be happening and where the story was going and coming from.

For Seveneves the roughest part for me was actually the end of act 1 with all the mistakes you could see a mile off and act 2 had a lot of really fun stuff I won't mention for spoilery reasons but the adaptation of the whip and chain stuff that came up win act 1 was honestly a lot of fun for me.