I upgraded to Oasis from Kindle Paperwhite. But my favorite Kindle is Kindle Keyboard 3. It is the easiest to hold among all Kindles. As it doesn't have touchscreen, I never worry about inadvertently turning the page or activating some menu. Only reason I got Paperwhite was because I wanted waterproof and builtin light.
PW is really awkward to hold especially when laying down in the bed.
Oasis is obviously ridiculously over-priced. But I got it because I got tired of PW. I like that Oasis has a large area to rest your thumb or fingers on, and also physical buttons definitely makes reading experience better. But it is not perfect, metal on back is too slippery, I still end up turning pages by accidents especially when switching hands. And did I mention it is way too expensive.
But it is still one of my favorite items, it is so much easier to read on it for extended period of time. I also send blog posts, news articles, docs, etc to Kindle via chrome extension and read them later when relaxing in the evening.
Also while I enjoy reading on Oasis, I am going back to physical books as much as possible. Mostly because I want to gift my books to my kids, and I don't know if Kindle would be around in 20 years or not. So the stuff I read on Kindle is mostly borrowed books from Prime library, personal docs, free books, or books that I am pretty sure will be useless in a few years like books on Kubernetes or other hot technologies.