Well i took England, and just formed the UK. I find it too easy to raise prestige, i just make more and more festivals. It's an exploit in my openion seince i use Spies to sow discontent in countries iam at war with. Is this intendet?.
I have to say that I agree on this point, while I love the addition of the culture system to get new advisors it does seem like it is too easy to keep culture high. Considering how long advisors live it is easy to keep three 5-6 star advisors at all times. Maybe they could make culture go down when you gain non-core provinces?