Which one would you recommend? I currently have a paperwhite. Can you see progress in percent and time left in book/chapter on the inkpad?
In Pocketbook (at least on my PB Color but the feature should be the same in all Pocketbook) You see the pages read / total pages and the pages remaining to the end of chapter. A page is a screen. It also can show the embedded page number. Of course You can disable them and to see a clear screen.

I don't own neither of them so it is difficult for me to recommend any of them. The Libra has a 7" screen and the Inkpad 3 has a 7.8 screen. The only thing I can say, if nobody that owns both can tell You a more informed opinion, is to check the features of them and to choose the one that fits Your preferences.
One thing to consider is availability. I don't know where you are, but Pocketbooks can be difficult to obtain in some places, and it still rankles that when I contacted Pocketbook to ask about buying one in my country, their reply was two sentences: "We don't sell there. Try ebay" Not very professional, imo.
I don't think so. Just page number and total pages... like "127/673." (This is with my PB615, which has older firmware. I'm charging the TL3 now to see if the choices are different. I think the only thing it does differently is let you use the ePub's built-in page numbering OR you can count each screen as a "page.")

(Checked my TL3, it does work the way described in the previous paragraph.)
Pages remaining in the chapter is newer than my TL3's firmware. But I read with a clear screen anyhow, so none of this really matters to me.