Battery holder differences
The "rechargable" holders have an additional connection to allow charging the batteries while in the radio while using an AC adapter. The regular holders do not have this additional connection. They are different to prevent attempting to recharge non-rechargable batteries for users that regularly use the AC adapter on their radio.
Personally, I never use an AC adapter and have rechargable batteries in both holders, which are charged up using a seperate charger. Assuming you never use an AC adapter for your radio, there is no significant difference between the two.