I'm GB, catholic and i plan to switch protestant soon.
Would this help me ?
-5% tech costs and stuff will be balanced by +10% from protestantism
but the missionaries (+2) and strength will greatly help me to conquer the world easily, more than the -5% tech and ideea costs costs, which is practically spam a couple less uselles building per 5 years
What do you think, it's worth it?
The big question is : would this lower the chances for provinces to randomly switch from catholic? I don't see anything to suggest that but it can be some hidden modifier.
The question is: will you be able to convert (to Prostestantism or Reformed) after picking the Counter Reformation? After all, it is meant to stop both, and help to reestablish the Catholic faith faster and easier ...
I still don't get why Counter-Reformation increases Tech-Cost as it should be the opposite: the Jesuits brought a lot of advancement and built countless schools and universities accross Europe.
But back on topic: yes, embracing the Counter-Reformation is one of things that decreases the chance of a province randomly converting to a Protestant religion (other things that decrease the chances are not being in northern Europe, religious idea group, being a Defender of Faith and having cardinals... so take care you don't have those if you want Protestantism to spread as much as possible).