I have had the slightly older Mars for about a year now. I wanted it for reading, of course, but my reading is generally on the Kindle (the app works great) and newspapers, in particular The Economist (the app works fairly well). The Mars has Micro USB, and a headphone jack I’ve literally never used – and also a MicroSD slot that I’ve used a bit for easy transfers. Chrome also works well, and no doubt other browsers do too.

My surprise was reading email on it – especially the lengthy standards emails I read, it’s perfect for it. Better yet, I don’t feel inclined to reply hastily, since typing is a bit of a pain – though I’ve experimented with a bluetooth keyboard and that does work really well. Twitter works fairly well, though the amount of animated media means that it struggles a bit.

A couple of things you don’t note:

At least on the Mars, you can turn on the Google Play Store as well as the Boyue store. There’s also the Good Ereader store you can use if you like.
All “e-ink” Android tablets are Android 6 – mine runs 6.0.1, which is frankly ancient. The reason is something to do with the graphics support in later versions not being compatible with the e-ink displays. The practical result of this is that the device is somewhat unsafe (I wouldn’t do banking on it, for example, and keep my work email off it too), and many apps just won’t be available, or won’t update.