...Endless Space is a decent compromise. It is a 4X game in space, and that's more or less all you need to know about it. It doesn't exactly go overboard with the innovation, but it's engrossing like a good 4X game should be, and it's over in hours rather than days. If you like 4X games, give it a whirl.
(And yes, I know that you can run MoO and MoO 2 in DOSbox/Boxer. I do, from time to time, even if I miss the true Mac version of MoO with native text rendering and arbitrarily large galaxy window.)