KOReader has a very clunky, overstuffed menu interface for configuring things, but once you have all of your preferences locked in, there’s rarely any need to mess with it anymore. Regular book navigation isn’t very different from any other eBook reader.
As a software developer with close to 30 years of experience, I find it continually astonishing when people say LLMs are useful to them for technical stuff. I already spend too much of my life debugging code I didn’t write. I don’t need to automatically churn out more technical debt to be responsible for!
One has no backlights. The other I keep on steady, low, purplish.