Masters of Orion 1 has a fast feel to it, with turns being burnt through rapidly (And with only 4 potential opponents, not much opposition), combine this with the way your industry works and you will be very rapidly climbing up the tech chain.
Masters of orion 2 has a slower feel to it, with up to 7 foes, but also has more customization options. It also has multiplayer, which MoO1 does not (The main menu for #1 is litterally only "Continue game" "Load game" "Save game" and "Quit to DOS".