PoE2 isn't even out and I haven't played D:OS2, so I can't really speak to the quality. I'd say both are worth a shot, but I'd play the original Pillers before the second as, unlike Divinity, the two are gonna be very interconnected
I know this is an older thread, but I just thought I'd say Divinity is by far the superior game in almost every way. Pillars 2 is still good though. The one advantage it has over Divinity is that it doesn't constantly make me want to bash my head in because of an overly complex quest or ridiculously difficult combat sequence, so maybe try out PoE2 first if you're not too familiar with CRPGs like this.
If i have to pick one.
DoS2. hands down, I think it's the more enjoyable game and it has a better main story. (also i like turnbased)
However. I strongly think both should be played.
PoE 2 has some of the best written dialouge and characters and player character defining roleplay I've seen in a long time.
Plus Maia totally stole my heart, she was so well written and man I really liked he character arcs.
Serafen was also amazing.