What is better and more rewarding for the Ummah of the Prophet (peace be upon him): to follow the Sunan that he consistently observed until his death, or to follow them along with the Sunan that he abandoned before his death?

The Hanafis divide the Sunan into two categories: Sunnah of Guidance (Sunnat al-Huda) and Additional Sunnahs (Sunnat al-Zawa'id). The Sunnah of Guidance is what the Prophet, peace and blessings be upon him, consistently observed and never abandoned. Its ruling is close to that of a Wajib (obligatory act), and abandoning it entails dispraise and dislike (Isaa'ah and Karahiya). As for the Additional Sunnahs, they are what the Prophet, peace and blessings be upon him, consistently observed but occasionally left. Abandoning them does not entail dispraise. They likened this to what the Prophet consistently observed in his habits, such as eating and dressing. This also includes prolonging recitation, bowing (ruku'), and prostrating (sujud).

The Hanafis did not mention in their books a division of Sunnahs into what the Prophet observed throughout his life and what he abandoned in his later years. It is possible that the Prophet's abandonment of some Sunnahs was out of fear that they might become obligatory upon the Ummah, such as the Qiyam of Ramadan and the Duha prayer. This fear ceased with his passing, peace and blessings be upon him, so the ruling for these is the desirability of consistently observing them.