Charles Donald Maclean, Dictionary of National Biography… (1912)
“ Some critics have occasionally complained that Willis voiced the reed stops on so heavy a wind pressure that the flue stops could not contend with them, so that the full power appeared to consist of reed stops only. But Willis's work was always marked by scrupulous conscientiousness and artistic insight. He could make every part of an organ from his own drawings. The workmanship and material of his instruments were admirable, down to the smallest detail, and he may justly be regarded as the greatest organ-builder of his time. ”
