stronger points:
The Titans expansion added another culture to the game(The Atlantians)which no doubt was alot of work. it did however change the balance of the game and the way people played the game. people hate change! it's sort of a "creature comfort" thing. everything being just so equals repetition equals control.
ES has been criticized for this new culture. even before the X-pack was released it seemed obvious to some that the new culture would be over powered. in some cases that is true but in others it's a matter of adaptation. regardless, adding a new culture was nice.
a new age was added for all to research. this is the Titan age. the only thing you can do in this age is build a Titan. Titans are very cool! i think most of us were excited to build our first Titan.
weaker points:
each pre existing culture got(with the exception of researching a Titan)only one new thing to do. that being, research a tech that in some cases is a little to little a little to late. basically, this looks as if it was an after thought, and probably was.
Titans were to easy to get and they were/are game enders. now before all the flames come, if someone doesn't rely on a Titan exclusively(they have an economy and military to back it)then the only true way to counter a Titan is to build one of your own. that quickly presented a problem as some cultures could jump through the ages much quicker/safer then others.
here's one that really baffles me where the Titans are concerned. the Titans are uber. so any little edge one might have over the other has fairly large repercussions. some major gods have techs that effect Titans. some don't. for instance, some can have a faster moving Titan, some a self healing Titan, and some can build it with far more ease then others. given the power of a Titan, i think that they should all be equal and these bonuses removed.
did i buy the X-pack? yes! do i regrete it? no! but i would have liked to have seen a few more new things to do for the old cultures.