just played the demo, three times, once with each race.
tried military with the greek, and had 6 cities at the 100th turn. (2 roman cities, 2 egyptian and 2 of my own ) ran into happiness problems but was lucky with getting "free" workers from the roman empire, so I could get some luxery items. the hoplite is very nice for early game beatings.
also getting the double exp from the honor social policy, and just placing a hoplite in range of a town, that you are at war against and press fortify for 4 exp per round.
then just played with egypt, building wonders and just having one city maxing it out, felt slow as some said in this thread.
with the persians I found a funny "abuse", if you find a barbarian camp that can only be accessed from one hex, and some city states are close by, place a immortal or warrior, something and just fortify and wait 10 turns or so, what happened to me was that 3 city states asked someone to remove said camp, and voila got 50 points with 3 city states, netting 4 food for my capital and 4 culture for my empire for 20 turns.
everything played at prince level.