Caulaincourt's memoirs are useful because he was actually at the centre of the things he was writing about bu they are only memoirs and need corrobation. Over the 1814 abdication Macdonald's Recollections are in close accord with Caulaincourt over the main points but there are plenty of discrepancies that need clarification.
Both of them were absolutely furious with Ney who, after their first return from Paris, wrote to Talleyrand giving his adherence to the new regime and claiming that he had persuaded Napoleon to abdicate. This, while he was still one of Napoleon's Commissioners! He did not mention it to his colleagues, who only found out when they got back to Paris.