I don't have a Paperwhite, but I have the Voyage and the Oasis. I wouldn't say that reading on the Oasis is a much better experience than reading on the Voyage. They're both good and I don't really prefer one to the other. The text on my Voyage is a tiny bit darker and sharper, but only a tiny bit. The Oasis, OTOH, is more comfortable to hold. I alternate between them.
I'm one of those people who just have to have page turn buttons, I dislike turning pages with touchscreen. The Voyage's page turn sensors do their job almost as well as the Oasis' buttons.
If you want a new reader with page-turn buttons, then you could also get the Voyage. It's a bit cheaper than the Oasis, but the reading experience is about as good, IMHO. Of course, it's all a matter of personal opinion and preference. There are those who prefer the Voyage, those who prefer the Oasis and those who consider the Paperwhite or even a basic kindle good enough.