Someone beat me to the punch on Eon, and a couple people on Marrow. Not sure how Eon didn't stick the landing. I thought it worked extremely well. Marrow was a really magnificent concept, I thought. I just wish the important characters weren't actually immortal. Their immortality made it harder to be engaged with them. But the concept is mind-boggling.
I wonder if Macroscope by Piers Anthony, notwithstanding the truly dreadful ending, qualifies as a BDO novel.
BTW, seems to me that the "dumb" doesn't ever really mean "stupid" in this context. Maybe more like "unforthcoming," or "mute"?