Interesting. So, while it allows players to actually use their units, it also makes them far more valuable (you lose them faster than you can replace them normally).
Yeah, but since everything is slowed down there's little functional difference.
On different speeds, it would still take you 6 units to conquer city X. It's just it takes you longer to produce those six units.
The main problem I found with Marathon setting is that it ended up being almost exactly the same, except with more dead time. Imagine a normal game, and then divide up each turn into 4 separate turns. Except, during those 4 turns, you can't accomplish more than you would in the 1 turn. You just have to "end turn" three times before you can do it.
That's not a perfect analogy, though, since the one area that ISN'T slowed down is unit movement. It's quite possible to, say, scout the entire contentent before you ever manage to finish the first settler, whereas in slower speeds, the settler would pop out before you finished.