I find Patricia's arrival in an Egyptian canal incredible, by which I mean "intellectually implausible," not "imaginative, amazing" etc. Eon raises several issues. The ones that I would like to see pursued further are:
can life survive a nuclear winter?;
what would it be like to explore other-dimensional spaces?;
is the mental technology described in this novel possible?;
if so, then how would that affect individual and social psychology?
Here is a moral question:
"If [terrestrials] were not purged mentally as well as physically, the conditions of their thinking would be such that strife and discord would tear the Earth apart again, in centuries if not sooner. They had to be mentally healthy to face the future...; there was no room for the kind of archaic, sick thinking that had lead to the Death in the first place." (pp. 489-490)
In HG Wells' In The Days Of The Comet, gas from a comet readjusts the balance between reason and emotion within each human being;
in Poul Anderson's Brain Wave, entering a new galactic region significantly increases the intelligence of every animal and human being on Earth;
in Greg Bear's Eon, mental technology can change people in these ways but would it be right to do it without their consent?
As yet, this question is academic since no one has the power to "purge" minds. But science fiction is the medium for testing such questions in advance.