To be honest, it depends. Lizwe sleeps till about 7-7:30...and sometimes a bit later/earlier depending on the night....or the previous day etc..so I work with those situations as they arise.
I found it better and easier in the beginning when we were implementing to have more of a structure..now that we're at 12 months I don't put a lot of emphasis on it.
Having said that all babies are different,and it may affect one child, where it did not affect another.