People who lived in the same time period as Shigemori often regarded him as a 'kind person who sent his messenger when something occurred ("Sankaiki" (diary by Tadachika NAKAYAMA)),' 'a person of a very beautiful mind ("Gukansho"),' and 'a very calm person even though he was braver than anyone ("Hyakurensho" (History book from the Kamakura period)),' and therefore, he was an excellent warrior yet at the same time calm and considerate (however, Kanezane KUJO disliked Shigemori and scorned him in his personal diary).
重盛に対する同時代人の評価は、「かくの如きの時、必ず使を送られ殊に芳心（親切な心）を致されるなり」（『山槐記』）、「イミジク心ウルハシク」（『愚管抄』）、「武勇時輩にすぐると雖も、心懆甚だ穏やかなり」（『百錬抄』）など好意的なものが多く、優れた武人であると同時に穏和で気配りのできる人物だった（ただし九条兼実は重盛を嫌っていて、非難の言葉を日記に記している）。