What task did the government do well under the articles of confederation?

When the Articles of Confederation were written, they intentionally gave more power to the states, and not to the central government. Unfortunately, the weakness of the central government created problems:  

1) Under the Articles there was only a unicameral legislature so that there was no separation of powers.  

2) The central government under the Articles was too weak since the majority of the power rested with the states.  

3) Congress, under the Articles, did not have the power to tax which meant that they could never put their finances in order.(eg. pay war debts, foster a diverse, healthy American economy.)  

4) In order to change or amend the Articles, unanimous approval of the states was required which essentially meant that changes to the Articles were impossible.  

5) For any major laws to pass they had to be approved by 9 or the 13 states which proved difficult to do so that even the normal business of running a government was difficult.  

6) Under the Articles, Congress did not have the power to regulate commerce which caused competition between states as well as diplomatic issues. (Each state had their own currency, of different values. Not every state accepted the other's currency. Each had different tax rates.)