These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
In Ring, Spinner-of-Rope and Michael Poole fly the Great Northern back in time by looping around a cosmic string.
Jim Bolder tricks the Qax into blowing up their own sun.
Humanity's war against the Xeelee was stupid and pointless, but their victory at the end of Exultant nonetheless qualifies, if only because forcing the Xeelee to vacate the Milky Way gives humanity a chance to progress and recover (and we do learn from Transcendent that things do indeed get better...for a while).
Even if it didn't work out and they went back to banging their heads against the Xeelee wall, humanity reached the point of near ascension to godhood in Transcendent. Not bad for a bunch of apes.
Retcon: There's some inconsistencies across the series, mainly between the earlier novels and the Destiny's Children books. Some of it is simply the result of a lot more light being shed on the period between the fall of the Qax and the end of Ring, but (for example) the fact that Xeelee-style FTL drives function as time machines, including the ability to create paradoxes is only revealed in Exultant, when one would have expected it to be mentioned earlier.
Tear Jerker: This troper outright wept at the end of Mayflower II, one of the stories in Resplendent. The immortal protagonist, guardian of the titular generation ship, has lost everyone dear to him, watched the onboard society unravel and then the inhabitants devolve over generations. Then two of the main characters of Exultant (who are now married with a baby) show up to rescue the pitiful descendants of the original crew and tell the protagonist he's done his job well. Finally able to rest, he sees the face of the lover he left behind before the voyage. It's left ambiguous whether it's a hologram the visitors left for him or just a hallucination, because it doesn't matter.