I played Vanilla for a long time, not really getting GS until about 6 months ago, and I still play Vanilla.
The difference between the two is striking and somewhat frustrating in terms of Single Player. Overall, I find Vanilla games more challenging and "fun", even though there are many aspects of GS that are more interesting and "fun".
For one thing, it seems to me like GS games end up dragging out too much. Both the Science and Culture victories come to a more rapid conclusion in V than GS, and in GS they seem to drag on past the point of being useful. Also, the fact that the victories come faster in V means that the AI is also able to threaten them more often, so in V I am often challenged to prevent the AI from winning, especially Kongo, Russia or Germany.
Great People are generally more useful in V, even though GS has some better GPs, especially Merchants. Essentially the GPs seem to have a bigger impact on the game in V than GS, because in GS other aspects of the game are relatively more powerful (you can get higher production, and more science, so the boosts are GPs are less important, etc.)
I find that in V the Science Victory is really all about the Space Race GPs. The amount of production needed to complete the Space Race is a lot in V compared to what you can produce, so the GPs that speed up the Space Race are critical. In addition the relationship between unlocking the Techs and doing the production was such that there was need to be able to have multiple Space Ports and kick off multiples projects at once, etc.
In GS, I find that I'm often waiting to research the next tech much longer than it takes to complete the projects, even if I haven't used any GPs at all, because its possible to get so much more production. 200+ production is easy to get in GS, whereas in V breaking 100 can be a challenge.
So in GS, the Space Race seems very anti-climactic, like a formality, whereas in V the Space Race is much more of a real race and getting those GPs is critical and often a challenge. Also in GS it seems like the GPs that give 100% boost are better than the flat production, whereas in V its the opposite.
As for Cultural victory. Again, in V, especially if Kongo or Russia are in the game (and you are not them), getting Cultural victory can be a real challenge. In GS it again seems to drag out longer, but be much more inevitable.
Yet, on the military front I think the AI puts up a better fight in GS, even though its still bad in the late game, its way better than the way the AI fights in V. In V the AI is useless in terms of fighting.
But many of the new mechanics and features in GS are quite fun and add a lot of depth to the game, the problem is that in spite of all that, the game feels less competitive. It feels less like a game and more like a Sim. V still feels more like a 4X strategy game, whereas GS feels much more like playing Sim City with lots of disasters and such to deal with. I find this disappointing because I'd like to play with the new features of GS in the way that the game feels in Vanilla.
The difference between the two is striking and somewhat frustrating in terms of Single Player. Overall, I find Vanilla games more challenging and "fun", even though there are many aspects of GS that are more interesting and "fun".
For one thing, it seems to me like GS games end up dragging out too much. Both the Science and Culture victories come to a more rapid conclusion in V than GS, and in GS they seem to drag on past the point of being useful. Also, the fact that the victories come faster in V means that the AI is also able to threaten them more often, so in V I am often challenged to prevent the AI from winning, especially Kongo, Russia or Germany.
Great People are generally more useful in V, even though GS has some better GPs, especially Merchants. Essentially the GPs seem to have a bigger impact on the game in V than GS, because in GS other aspects of the game are relatively more powerful (you can get higher production, and more science, so the boosts are GPs are less important, etc.)
I find that in V the Science Victory is really all about the Space Race GPs. The amount of production needed to complete the Space Race is a lot in V compared to what you can produce, so the GPs that speed up the Space Race are critical. In addition the relationship between unlocking the Techs and doing the production was such that there was need to be able to have multiple Space Ports and kick off multiples projects at once, etc.
In GS, I find that I'm often waiting to research the next tech much longer than it takes to complete the projects, even if I haven't used any GPs at all, because its possible to get so much more production. 200+ production is easy to get in GS, whereas in V breaking 100 can be a challenge.
So in GS, the Space Race seems very anti-climactic, like a formality, whereas in V the Space Race is much more of a real race and getting those GPs is critical and often a challenge. Also in GS it seems like the GPs that give 100% boost are better than the flat production, whereas in V its the opposite.
As for Cultural victory. Again, in V, especially if Kongo or Russia are in the game (and you are not them), getting Cultural victory can be a real challenge. In GS it again seems to drag out longer, but be much more inevitable.
Yet, on the military front I think the AI puts up a better fight in GS, even though its still bad in the late game, its way better than the way the AI fights in V. In V the AI is useless in terms of fighting.
But many of the new mechanics and features in GS are quite fun and add a lot of depth to the game, the problem is that in spite of all that, the game feels less competitive. It feels less like a game and more like a Sim. V still feels more like a 4X strategy game, whereas GS feels much more like playing Sim City with lots of disasters and such to deal with. I find this disappointing because I'd like to play with the new features of GS in the way that the game feels in Vanilla.