I sometimes play religious economy early, but by the time I get to Philosophy (prerequisite for Angkor Watt), I am usually in the heat of the race to discover Liberalism, and so am more interested in generating Great Scientists to help bulb Education or Liberalism rather than get more Great Prophets. Sometimes I build it anyway just to pick up the 8 culture points, but usually not.
You can settle great prophets / build shrines and run a higher science rate instead of bulging to liberalism, plus Angkor way makes every priest specialist generate 2 hammers and 1 gold.
Ankgor wat is more for boosting production under a gold focused religious economy, when played right you don't need to focus on great scientists. You can use the extra gold generated to run a much higher science rate. I've tried both great prophet and great merchant focused farms and find them to be much more powerful than bulbing liberalism with GSs. The only problem is that on Immortal / Diety, getting the required wonders built is very hard, though I have been managing to get Oracle and AP built on several playthroughs with Justinian on Immortal difficulty, but mostly due to abusing his imperialistic trait to save loads of early game production and get cities built faster. I don't think I can manage the same with Saladin, maybe I can with rameses, but obelisks are meh.
Angkor wat is the most fun when playing unrestricted leaders and Ramesses or Hatshepsut of Arabia because the bonus priest slots never expire (Madrassas are too much better than Obelisks, not just two extra permanent priest slots, but also more culture).