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.
Designated Villain: Burton in the 2010 version, since he's actually trying to save humanity from an eternity of suffering inside of an alien wargame, while the heroes are actually working to continue it?!
Jerkass Has a Point / Strawman Has a Point: Burton in the 2010 version, since at no point is it really shown or explained why continuing the Riverworld experiment would actually be a good thing for anyone?
Relationship Writing Fumble: In the 2010 version, Matt has more chemistry with Tomoe than his actual love interest, mostly due to Jessie having very little screentime that aren't flashbacks. Considering that we later learn they only dated for two months, later entered a relationship with Burton and actually somewhat supports his goal, she's essentially a Shallow Love Interest.
Values Dissonance: A Victorian Englishwoman and a Neanderthal caveman are on the same team. Eventually both adapt to each others' quirks, like cannibalism and clothing.