This report summarizes the novel features of the title complex so far investigated. (EDO-TTF)(2)PF6 showed the first-order metal-insulator (MI) transition at 280 K, of which mechanism was assigned to the cooperated one of Peierls, charge-ordering, and order-disorder transitions. The origin of the mixing of the transition mechanisms is regarded to be the distinct molecular deformation during the phase transition. In the examination of the effect of a pulsed laser light, the insulating phase showed the ultra-fast and highly efficient photo-induced phase transition, which needed ca. 1.5 ps and one photon per ca. 500 donor molecules to produce the highly conductive metastable state. The preliminary results of the thermally induced MI transition observed in the newly obtained isostructural complexes are also mentioned.