Guide: The best phones and tablets for Android LineageOS (Officially Supported)
The vast majority of Android device buyers don't know or care what a custom ROM is. And that's completely fine - a phone or tablet's stock ROM will be enough for 99.9% of potential users. But for the 0.1% that like to tinker (or lust after additional features), the development community surrounding a given device can drastically impact the value. Your purchase can become a much better deal if there is a wealth of custom ROM options available, extending its lifespan for possibly years (and nearly a decade for the HD2).
There are quite a few popular custom ROMs in the wild, but LineageOS is probably one of the best overall. It has a huge community of developers, constantly adds new features, and supports a whopping 182 devices (at the time of writing) with official builds. CyanogenMod was the ROM of choice for users just wanting a basic stock experience, and Lineage Project has done a great job of continuing that effort.