There are a couple of things I wish Amazon changed. It still uses an old microUSB charger, one of the few I know of that still do. Most new gadgets have adopted the newer USB-C standard, which can help charge devices faster. Plus, I'm more likely to have a USB-C cord in my travel bag than a microUSB cable, even though the Kindle ships with one. It's just a little less convenient.
The 4 GB of storage is plenty for me, since it still can hold thousands of books. But you'll want more storage if you're planning to use the Audible audiobook feature. You can't upgrade the storage, so the next best option is to consider the Kindle Paperwhite, which starts with 8 GB of storage.
Also, the new Kindle it isn't water resistant like the Kindle Paperwhite or $249 Kindle Oasis. Consider another model if you're planning to read on an inner-tube in the pool or at the beach.
It doesn't come with a case either. As a long-time Kindle owner I've found the screens can be prone to scratching if you leave them in a bag. I recommend buying the $30 fabric cover, which Amazon sells.
Finally, the interface felt slow to me at times, particularly when I was trying to back out of a book or move through the Kindle Store to find new books. It's not a deal breaker, but it just didn't feel as fluid as the experience on Amazon's more expensive Kindles.