Using CPU Miner, it's unclear to me whether I need to specify the payout address using the --coinbase-addr argument or whether simply specifying the BTC address as the username, -u is sufficient.  Is there a difference in either of the following?  Both "seem" to work, but not knowing what's really occurring on the backend, I want to be sure I'm using it properly.  Thanks.

minerd -o stratum+tcp://solo.ckpool.org:3333 -u XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --coinbase-addr=XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -p blah -a sha256d

or

minerd -o stratum+tcp://solo.ckpool.org:3333 -u XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX -p blah -a sha256d