Depends what a little bit on what you’re looking for. As a disclaimer, I am a Kobo user. Whether you go with a single purpose device or a multipurpose device like the boox depends a little bit on how focused you want to be able to be. I like my dedicated E reader because it makes it harder for me to just pop over into some other application to “I’ll just check something, quickly” because for me those never end up quick. Kobo has a good store, with a nice interface and the DRM is easy to strip. It also works well with side loading DRM-free content.
A boox would give you more storefronts to choose from but you’re more locked in to whatever DRM those stores choose.