The extra battery makes this product worth it in itself but I'll write about my other opinions too. For starters, I HATE blister packaging and this product comes neatly in a box. Which is a huge plus. Did I also mention it comes with an extra battery? The charger itself has a small footprint which can easily be hidden behind other things. The main idea for something like this is to prevent you from having to use the dreaded play/charge kit and this is where it delivers. Dead battery? No problem, just swap in a new one and keep on going. Only issue comes around when you have more than one person playing and need more batteries, but those are available as well. It's an authentic Microsoft product so you'll be getting a high quality item while padding Mr. Gates' pockets nicely. The rapid charge function works well and it does manage to charge the battery in about 20 minutes. I usually keep the charger unplugged most of the time because it has quite a bit of vampire draw with nothing plugged in, which is the reason for my 4 star rating.
Overall, this is a good product that's well made and worth your money. I would recommend it any day.