I know the developers have boosted the Advent's culture in a number of ways (by allowing it to help them block phase missiles and such), but has any thought been given to the rate at which culture actually takes out a planet?
Here's a common scenario in small or medium random galaxies.
- I notice enemy culture creeping down the phase lane towards my outlying planets. Since I haven't spread my own culture yet or moved my capital planet, let's say my allegiance there is around 60%
- I finish whatever I'm currently researching in the civilian tech tree
- I walk out of the room for a few minutes, to use the bathroom or grab a snack
- I sit down and begin researching culture generators
- I build a culture generator at the afflicted planet; by this time, its allegiance has dropped to around 30%
- Problem solved
If I'm REALLY unlucky and the planet's allegiance is around 30%, I'll move a capital ship into orbit. This solves the problem almost immediately, unless the opposing empire has invested in three or four culture generators. Even then, I still have plenty of time to react and neutralize the threat with a minimum of investment.
The point I'm trying to make here is that, in my experience, culture simply isn't a threat, and there is no incentive to engage in culture wars with opposing empires.
Just for fun, I played a game against a cruel AI. Instead of bombarding their planets, I wiped their systems clean of orbital structures and positioned a starbase in each one to prevent respawns. Then I let culture do its work.
Two hours later, I won.
I feel that culture should be a valid research avenue and a credible threat to an empire. Players should be able to benefit from tech-switching and using culture to pressure an opposing player. Increasing the rate at which culture depletes planetary allegiance and reducing the rate at which culture loses potency after it passes through a gravity well would be an excellent start.
That said, maybe the devs have already done that, and I'm just unaware of it. If so, feel free to correct me.