Sahl bin Sa`d (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "People will continue to adhere to good as long as they hasten to break the Saum (fasting)."[Al-Bukhari and Muslim].
"Adhere to good" here means welfare of the religion as well as that of this world. Breaking the Saum early does not mean that it is terminated before the prescribed time. What it really means is without any delay after the sunset. One should not delay it for the mere reason that the rigour one has gone through in the Saum should be enhanced further, as is done by some Sufi. There is no merit in such things because the real merit lies in following the Sunnah of the Prophet (PBUH). Welfare of the Muslims will, therefore, come in the share of the Muslims because of their following the Prophet's Sunnah of breaking the Saum in the early moments of the prescribed time.