i do. always. unless i'm playing one of my very rare "force myself to go to war early and kill 'em all" games. i am a builder, and somewhat of a culture-monger, at heart. i have this "well i'm not really ready to declare war yet" thing and i have to force myself, so those games are very very rare.
There's nothing wrong with that policy. Just declare war when you've run out of expansion room, and there's nowhere to grow except into another empire
the ideal of course is to have multiple monasteries in science cities before SciM for +10% science. at the very least, i do everything possible to have at least one monastery of each religion i have somewhere in my empire by the time i hit scientific method, so that the opportunity to spread happiness around in free religion times is there.
I suppose I didn't really think about the science boost. +10% is not a lot compared to other science buildings. If I want science, I'm building Libraries/Universities/Observatories. Even Markets and Grocers will contribute more to your overall research (albeit indirectly), unless you are running mainly a specialist economy or your science slider is running at 80% or more.
The ability to stack multiple monasteries is nice. I hadn't considered that.
Do you know whether or not the +10% science still applies after scientific method?
My experience is that I never build monasteries because, before Scientific Method, there is always something more important to be building. There are better ways to get culture, better ways to get science, and since I'm usually running OR (for the +25% construction bonus), I can get missionaries without needing monasteries.
I suppose it's nice to tuck away 1 or 2 monasteries before switching to Free Religion. However, it's rare that I switch to FR before Scientific Method. It's just too hard for me to give up the +25% construction bonus from OR.
Monasteries get a little more value if you have the Spiral Minaret or the University of Sankore, but otherwise I just can't seem to make the time for Monasteries.
sometimes i run OR but don't pick a state religion if i don't have lib yet for FR. could be i don't have monasteries in the right cities yet, maybe picking a state religion would be dangerous considering my neighbors, maybe i want the culture from multiple religions and multiple holy cities (that's a big one in culture games). OR costs more than paganism, but i'm able to build missionaries for any religion a city has, and having no state religion avoids "heathen religion" modifiers. later i can change to whatever civic, pick a religion, whatever, but in the meantime i've been able to spread my religions to multiple cities.
I haven't tried running OR without picking a state religion. I don't think the maintenance costs are worth it just for the missionaries. In that scenario, I think I'd just stay pagan, build the monastery, and move on. But, given the choice between +1

and getting rid of "religious heathen" modifiers, I'd rather take the happy face. My enemies can go to Hell (or Hades, Gehenna, Neraka, or wherever their "heathen religion" sends them when they die)
if i do have a state religion, monasteries are priceless pre-SciM if i'm running theocracy and want that bonuses in cities where i didn't get natural spread. if i have the holy city, i like spreading my state religion just for the line-of-sight spying, even if my intent is just selected cities, not actual conversion. depends on the political situation of course.
Yes, but if I'm running Theocracy, I'm building soldiers, not missionaries. However, I can see why it would be useful to bring missionaries along to war (to get culture running in conquered cities ASAP).
I also haven't really given Pacifism a try. I'm too much of a warmonger to be willing to pay through the nose for unit upkeep. But I can see the benefits of Monasteries under Pacifism as well. Also, if I have an isolated start, Pacifism can help me lightbulb my way to optics and get to the other continent!
i'm also a big fan of using religion to manipulate diplomacy, spreading selected ones around when i have the time/hammers. sometimes not just my own religion, different flavors if i have them, to stir up trouble between other parties without having to bribe anybody.
I suppose that the main reason why I've avoided monasteries is because I'm usually running OR (even past Liberalism). Maybe by building monasteries, I can liberate myself from the need to stay in OR all the time
