Feudalism is good only for some types of games. -when having few rives and playing no Agr civ (no cheap Aquaducts) -poor terrian -few luxuries -when you are not already in some other governmet, or you are Religious With such setup, getting 7+ pop cities is huge investment. Taking on Repulbic would be too risky without luxuries and steep upkeep cost (only one free unit per <6pop city city) Getting Monarchy on the other hand just gives you "great" opporunity to lose some money (since you can freely support only 2 units per city at most). In those cases with Feudalism you'll get most income. It's best investment if you are Religious, so you can switch easy and switch out when needed. But, if you are not Religious, it's probably only good choice if you already didn't switched to other govenments already. And that is more common on higher difficulty levels, when you have no times to research optional techs. It served me well on Deity game I played once.