First thing you will notice as you open Kindle Oasis is how small it looks. On a first glance one would tell it has smaller screen than previous Kindles. However, it is all an illusion as screen is well known and lowed 6" diagonal.
I find screen as good as one on Kindle Voyage and, although Amazon claims Oasis' is better, I cannot say anything bad about the either. My eyes see no significant difference between them. Curiously Oasis abandoned ambient-controlled backlight present on Voyage and I can only say good riddance.
After a long time we finally have physical buttons back. I don't find them as enjoyable as ones on grandpa Kindle 2 but they are better than press-buttons on Kindle Voyage. Unfortunately there is no way to turn off swipe gestures on the touch screen so accidental page turns are still possible.
It took a while but we finally have a Kindle suitable for lefties among us. As device is mostly symmetric, simple rotation will make it fit in your left hand as comfortable as it was in the right. Even better, it will auto-rotate screen as soon as you do it. Only drawback is that suddenly power button is on the bottom and not possible to press using left hand. It is a minor thing and completely ignorable if you keep cover on and rely on auto-wake.
One of the more important things about any Kindle for me is how it fits and here Oasis is perfect. A slight tapering on the back leaves just enough place for the tip of your fingers to grab and rubbery material they are using makes holding it really comfortable. Unfortunately, that all goes away as soon as you put the cover.
With the cover on, Oasis becomes a bit unwieldy for me. I struggle to hold it both securely and comfortable for any longer duration as nice resting place for my fingers is suddenly displaced by a step requiring me to essentially keep my fingers straight. I found myself simply removing cover for any longer reading. Someone with smaller hands might not have these issues.
Cover itself is beautifully looking but thinness of leather doesn't really instill much faith it will age well. As it is slightly thicker than Oasis itself, it sort-of seems as an afterthought and a way to offset small capacity of the main battery. It does that reasonably well as I can definitely say it outlasts both Voyage and Paperwhite.
All said, I find Oasis a beautiful albeit expensive device. I believe Kindle Paperwhite is a great benchmark for enjoyable reading and I wouldn't be dreadfully punished if it was only device I could use. Voyage enhances that experience and Oasis brings it near to the perfection. But, as always, the great enjoyment comes at a great cost.