Seconding front-lit e-ink: the latest Paperwhite and Kobo Clara 2E both let you schedule the warm light for evenings and they have a dark mode you can try which, yeah if you want to save money, a refurbished Paperwhite (11th gen) or a used Kobo Clara HD still gives you adjustable warmth and a comfortable 6-inch size. One extra tip: on e-ink, ultra-low brightness or inverted text can feel harsher for some eyes, so keep the light a notch up and only use dark mode if it genuinely feels better.
Three months is the usual guideline but many heads have “indicator” bristles that fade to about half color as a replace-now cue, and it’s smart to swap sooner after a cold or flu. If yours is fraying early, you’re probably pressing too hard - let the brush do the work, consider a “sensitive” head, and in hard water pop the head off after rinsing to dry the shaft and give a quick weekly vinegar rinse. To keep costs down, multipacks or decent third‑party compatibles are fine, and rotating between two heads lets each dry completely and can slow wear.