This isn't quite the top of the line for Kindles, but it's close. That honor would go to the Scribe, with the Oasis possibly taking second place, though we haven't seen a new Oasis in a while. It sports more memory than the regular Paperwhite, and I think that's particularly worth it if you're using Audible on the device. It would take a lot of text-based books to fill 8 gig never mind 16.
I want to compare ereaders, then compare ebooks to print.
If you are going to use this for audiobooks, it's hard to ignore the Nook from B&N as a competitor to this. The Glowlight 4 is about the same size as this and the 4 plus is a bit larger. All of these sport 32 gig of memory, are waterproof, and have about the same screen type.
The advantage of the Nook is you get a 3.5mm headphone jack as well as being able to connect headphones via Bluetooth. The Kindle is limited to Bluetooth.
The advantages of the Kindle are first that it supports Audible. If you have a subscription already, that becomes a no-brainer. If not, there are a lot of titles on Audible that B&N doesn't have. If those interest you, you're better off with the Kindle, and you'll want the larger memory.
Second, transfering your own documents wirelessly to the device is substantially easier on Kindle. Just email it, or use the website, or send it to the app on your phone. Nook requires you use a USB cable and then find the right folder to put it in. This is a win for the Kindle, but any Kindle, not just Paperwhite Signature.
Third, market dominance. The demise of Nook is often predicted (I don't think they're going anywhere, but that's merely my prediction based on market share over time) but no one in their right mind thinks Kindle, with a commanding 80+% market share at the time of this review, is going anywhere.
For free books, Kindle has the monthly subscription to unlimited, Nook gives out a free books (or sometimes audiobook) every Friday. Prime subscribers can pick a free book (sometimes two) from a small selection at the beginning of the month. Overall, I'll call that a toss up.
I use both, but if I could have only one, I'd go with the Kindle.
If you're deciding between Kindles, the Oasis is smaller despite having a slightly larget screen and physical buttons (the bezel is much smaller) and it has cellular. The Paperwhite Signature has USB-C (not a big deal in my opinion) and wireless charging (and the stand they sell for that is absolutely amazing). The Paperwhite Signature is also substantially less expensive.
The Scribe supports the pen and has built in notebooks, making it kind of a hybrid between the Supernote and the Kindle. That's the big win there. The win for the Paperwhite Signature is that it's waterproof, smaller, and less expensive.
The basic Kindle is also worth looking at on a budget. It has less memory and isn't waterproof, but it's extremely affordable. This is the one I'd take with me into situations where I'd worry about it getting lost or damaged because it's the easiest to replace. This is also the one I'd give a kid, for the same reason, and also the one I'd suggest someone start on if they're not sure if they'll like ebooks. It really is a nice device. I use mine a lot.
The Paperwhite regular sports less memory, but is a fine contender if you only want ebooks, no audio. You can only go up to 16 gig memory there, no wireless charging. It's front lit, but not automatically adjusting and it has ads.
On the topic of ads, I've seen memes that seem to suggest they pop up while reading. While this model has no ads, if you're considering another don't let that stop you. They are on the sleep screen. They don't interfere with reading. It's one of the myths told by the "dead tree only" crowd. The others are:
You can't dogear them. Well, you can, only you can also remove the dogear without leaving a trace, so that's actually a win in the ebook column.
You can't mark them up. Again, you can and you can undo, but because the space is not limited to the page, you can add larger notes here than would be supported in print books, particularly those with thin margins.
You can't use them if the battery dies. The battery lasts weeks for me and I'm a heavy reader. I have never found myself unable to use my Kindle because I was in some foresaken wasteland without access to power. I can even recharge my device for free on the bus if I have my cable with me (I usually do). I have found myself reading a book I lost interest in while out and about and using a Kindle (or any ereader), that's no issue. With print it used to be.
You can't use it near water. This one is waterproof. I've never seen a print book that wasn't destroyed if you got it soaking wet. I'm not even sure where that myth came from. I can say my Paperwhite Signature fell into a sink full of water and didn't care.
You retain more from print books. I'm putting this one in the myth column because I don't trust the methodology. First, they were only using iPads with notifications turned on. Then, when enough people cried, foul they used the Kindle DX (giant, wonderful device; I wish they'd revamp and reintroduce those). Only they only selected people who'd never used one before.
I recently spoke to someone involved and we discussed why they didn't include audiobooks. Participants get 15 minutes to read about 25 pages. The print folk just get the book and start reading. The ebook folk get a lecture on how to use it before they start reading, but the lecture cuts into the 15 minutes. Ever wonder why the studies also show people on ebooks read faster? If they threw in audiobooks they'd have to allow enough time for participants to hear the story at normal speed.
I want an apples to apples comparison, with people experienced with ebooks and identical reading times before I'll trust this. On a side note, if you want to remember what you read better regardless of medium, check out Moonwalking with Einstein (available on Kindle).
One thing the "dead tree only" crowd won't talk about is the environmental impact. The impact of ebooks has always been better than that of print, but we've come so far in so little time, that a modern ereader like this one has the same impact as 14 print books. Once you read your 15th book on this, you net an environmental win.
Another thing is accessibility. Any book can transform immediately into a large print book while remaining light and easy to hold and carry.
Then there's lighting and the ability to read anywhere. I read in bed with the lights off. If you have a kid who "sneaks" a book under the cover, this makes it easier and reduces eye strain.
Then there's the ability to text search for something you forgot and want to reference. I can barely stand print books for the inability to find some random tidbit easily.
That and you get to keep your entire library. I'll always have nightmares about helping a little old lady who loves to read move into assisted living and having to discard the bulk of her library. The bulk of my library sits in my purse. And you can have the same book on multiple "shelves". That's how I get around the "is Star Wars science fiction or fantasy" debate. It lives in both.
So for me, ebooks win overall, and if I have to go with one line, it's Kindle. Amongst the Kindle, my favorite is usually the Scribe for non-fiction (for the ability to take notes) and this for fiction (for the most comfortable form factor) with the base model being used in some situations.