Though your Xbox One controller runs on AA batteries and includes one pair of them, it's so much nicer to have the Play and Charge Kit rather than burning through costly AA batteries. Even rechargeable AA batteries aren't as good, they don't last quite as long per discharge, and you have to remove them to recharge them. It's much easier to just plug in the charging cable when your juice is low.
These rechargeable batteries seem a little smaller than the Xbox 360 ones, but worked great all through my Xbox One's launch night. The only very minor downside is it takes a few seconds longer to swap these batteries out than it did to swap out an Xbox 360 battery, but I like the tradeoff of having the Xbox One controller be slimmer and sleeker since there isn't a big battery jutting out the back. The swap time doesn't really matter anyway since you use the cable to recharge it, where on the 360 I usually swapped one out of my Quick Charge kit (Microsoft hasn't yet released a similar product for the Xbox One yet).
The charging cable is sufficiently long to play from my couch (8 feet away from my TV). Took an hour or so for the initial charging to finish from whatever capacity percentage these come from the factory. Don't bother with the third-party junk batteries. While the cable is just a basic micro USB and interchangeable, off-brand rechargeable batteries are rarely worth bothering with for the small difference in price. The cable itself seems pretty high quality too though, it snaps in and has a very solid connection, which I like.
My only complaint isn't about this product, but about the Xbox One design. The single USB port is on the console's left side instead of how the Xbox 360 has two ports on the front. This makes it not reach quite as far, and is also more risky in the event of someone tripping over the cable. Instead of it just yanking out, it might tug the cord in a bad way and damage the cable or the USB port.
I recommend buying the bundle with the controller for a $10 discount though ($75 instead of $60+$25=$85), unless you only ever plan on having one controller I suppose. Amazon is sold out of those at the time of this review, but my local Best Buy and Walmart still had stacks of them, so you may want to try a local store.
Update 2013.11.24: I've gotten at least about 20 hours of on-time without the battery dying since I got my Xbox One. I didn't go until it died before plugging in the cable, but it seems to have about as much life in it as the old Xbox 360 rechargeables. Maybe even a little bit more since all my 360 ones are aging and gradually losing their charge, though this one will probably do the same over time.