Okay, initial thoughts.
Shape
I received yesterday afternoon. I've seen plenty of videos and pictures of the Oasis but it looked different in person than I figured. It's smaller and "cuter", but this is a good surprise. I like the shape more than I thought I would and it's not as bulky/awkward as I feared it would be. That's one of the reasons I held off on getting this so long, and it turned out to be a moot point anyway, go figure.
I got the Champagne Gold color. I like it, the color is subdued a bit but I may end up just getting a sleeve for it instead of a case to not hide the color, and it's extremely light to hold. There are those neat sleeves from decalgirl too, hm.
It's taken me a bit to get used to the back when holding because of just not being used to it, but it's not an issue so far and I don't think it will be. I think it's just something to get used to.
I haven't had a freezing metal back issue some have said. Sometimes it's slightly cool at first when I first hold it, but I like that. I live in Florida, though, so I may never run into the cold issue I've seen others reporting.
Speed/Buttons
I know video reviews said it and the PW4 were about the same speed, and on the videos it showed to be so, but this seems much faster than my PW4 so far. Again, mileage may vary for that with devices.
I'm in love with the buttons already. I haven't had a chance to read much at all, unfortunately. I did browse the library with the buttons and tested them and can already see I'm going to love them. This may be the issue with speed, perhaps the buttons are more responsive or I just got lucky on that.
Screen
My screen is uniform and seems well done with lighting. I don't notice anything odd or off about the screen so no complaints. The feel seems different somehow than the flushed PW4 screen, I'm sure there's a tech reason, or else again it could just be my imagination. Since I can use the buttons now, I won't have to touch the screen as much, which is good since I always leave smudges on these screens.
I'm liking the larger screen. I read very briefly just to test this with different font sizes. It does feel more comfortable to have slightly larger size and screen real estate and is making a difference. Feels cleaner for the eyes somehow, hard to explain.
I have not been able to test out the warm light at all. I spent hours last night adding books to it while watching videos with my son. I left on the charger all night. The indexing is draining the battery, but that does happen. I charged to 100 percent, then was adding books, and it went down to about 50% within a few hours. I looked this morning and it's still indexing over 1,000 items. Since it's still busy at work there, I won't be able to fully test real battery yet. Busy day so far, and no reading time at all, plus I'm trying to load it at the beginning.
I put the nightlight on to see if I like that where it's supposed to adjust. I have the brightness turned up, but also left the "auto brightness" on. As I actually read with the device, I may adjust that stuff later. I won't be able to tell unless I'm reading for periods of time. Since I haven't been able to see it in action, not sure yet how well this works or if its something I'll notice.
I left the warmth setting to be where it's supposed to change sunset to sunrise without putting in specified times to adjust. I haven't been able to tell gradual warmth impressions yet, so there's still plenty to discover.
So far I'm loving it and am happy with my purchase