I usually use my GP in the following ways:
Great Scientist - Build an Academy. If my best science cities already have Academies, become a super specialist.
Great Engineer - If there's a Wonder that I'm worried about an opponent getting first, rush it. Otherwise, become a super specialist.
Great Merchant - Unless late in game, become a super specialist. Might cash it out if I'm in a dire need for cash, but usually I don't that much use for money.
Great Prophet - Religious wonders. If I've already build the wonder of the religion I'm spreading and don't have other spread-out ones, become a super specialist.
Great Artist - Culture bomb. If I have no cities where culture bombing is useful, become a super specialist.
As you might notice, I practically never exchange a GP for a tech. Doing so would seem like a waste to me - sure, I get a tech a couple of turns earlier than otherwise, but turning a GP into a specialist gives a much bigger long-term advantage. On a similar token, I avoid Engineer-rushing Wonders unless I fear I'll lose the race to build one - it'll be much more useful to get those hammers as a permanent addition to the city's production. The obvious exceptions are in the late game, when there's no time to be thinking in long term any more.
I don't usually have many Golden Ages, either - if I happen to get two GPs at around the same time I'll use them to start a GA, but rarely actually save up Great People to achieve one. I've never spent more than two Great People to start a Golden Age, either, as I'm a bit unsure of whether it pays off.
Any other thoughts? Especially about when is it a good idea to save up Great People for a Golden Age and when isn't it?
Great Scientist - Build an Academy. If my best science cities already have Academies, become a super specialist.
Great Engineer - If there's a Wonder that I'm worried about an opponent getting first, rush it. Otherwise, become a super specialist.
Great Merchant - Unless late in game, become a super specialist. Might cash it out if I'm in a dire need for cash, but usually I don't that much use for money.
Great Prophet - Religious wonders. If I've already build the wonder of the religion I'm spreading and don't have other spread-out ones, become a super specialist.
Great Artist - Culture bomb. If I have no cities where culture bombing is useful, become a super specialist.
As you might notice, I practically never exchange a GP for a tech. Doing so would seem like a waste to me - sure, I get a tech a couple of turns earlier than otherwise, but turning a GP into a specialist gives a much bigger long-term advantage. On a similar token, I avoid Engineer-rushing Wonders unless I fear I'll lose the race to build one - it'll be much more useful to get those hammers as a permanent addition to the city's production. The obvious exceptions are in the late game, when there's no time to be thinking in long term any more.
I don't usually have many Golden Ages, either - if I happen to get two GPs at around the same time I'll use them to start a GA, but rarely actually save up Great People to achieve one. I've never spent more than two Great People to start a Golden Age, either, as I'm a bit unsure of whether it pays off.
Any other thoughts? Especially about when is it a good idea to save up Great People for a Golden Age and when isn't it?