1. Overall quality of the dock and the batteries is very good.
2. The batteries last quite a bit longer than the official Microsoft play and charge batteries (used it for 4 days in a row without charging).
3. Charges in roughly 3 hours.
4. Controller slides into the dock with ease.
2. Not sure if you can get replacement batteries if these stop working (I have looked but cant find any).
Overall I give it 5/5 stars because of how great the battery life is, its pricey but worth it.