The Apple rechargeable batteries work fine. Most reviews are positive. The negative reviews seem to focus on two issues:
1) The computer does not show 100% for fully charged batteries. That's normal. Rechargeable use different chemistry, and the voltage at full charge is less than that of non-rechargeables, and the computer has no way of knowing what type battery is in use.. They still work for weeks, and the computer gives the low charge warning at the correct time.
2) The charger's orange light flashes. That means the battery is not making good contact with the charger. Cleaning the contact or battery, or just wiggling the battery will fix this, and it usually won't happen again. It's a lot better that the charger lets you know of the problem rather than just not charging it.