* I assume most practitioners of religion are on the “less” side of belief, whatever they profess. The extreme version of this would be “there are no theists outside a foxhole.”

* I assume that the universes painted by different religions are not equally nice. There are substantial choices to be made.

* I’m not interested in the masses who accept default choices, eg the person who stays in their hometown, but the [wanna be] rationalist.

By the way, “all religions are true” could be simplified away — you get to chose the universe you are born into, ie one in which the religion of your choice is true.

It seems like saying, “The town a few miles away is as nice as this one, why don’t you live there?” To which anyone would respond, “If it’s just as nice as this one, why move?”

I think you also missed “What if…” Re-read that paragraph.

Now if you thatought the question was what a rationalist should consider sans that thought experiment, I would say completely ignore religions’ systems of ridiculous falsehoods, I mean beliefs, only evaluate their practicies and community.

Religion has always been a means of identifying with an in-group. Judaism and Hinduism, for instance, are pretty explicit about this: this is a religion for our people. (Not to say there haven’t been evangelist Jews, but they’re the exception rather than the rule.)

Even for religions that want everybody to get in their boat, like Islam and Christianity, religion is a major part of self-identity for many believers — often down to the particular sect or ideology. A Jesus fish on the bumper sticker is much more about “this is who I am” than “this is who you should be” (whether the car’s owner thinks so or not).

Religion is still one of the major factors in determining “nations” of people. Nowadays, we’re more likely to consider ethnic and linguistic aspects, but that doesn’t mean religion isn’t significant (and historically it was certainly seen as a bigger factor than today).

So your question of how to “rationally” choose a religion only makes sense if religion is merely a system of beliefs. In fact, religion is always also a system of practices, ranging from relatively internal practices (self-identification) to obviously external ones (communal worship and celebrations). Participating in those practices can provide very tangible benefits.

No god offers nothing. All any god has to do to beat no god is offer some net benefit.

IMO, choosing a religion is a lot like accepting axioms in any other system. I wrote more on that here: http://csarven.ca/systems-and-choices , if you’d like to give it a read. I think, at the end of the day, it is more or less a pragmatic decision.