The "luring the Death Star into a trap" rationale works except for one small quibble: the Death Star plans had NOT been analyzed yet. Leia didn't know whether or not there was a weakness in the DS that they could exploit. Remember this?

Leia said:

The technical readouts of that battle station. I only hope that when the data's analyzed a weakness can be found.

And even if she was completely confident that a weakness would be found, she had no way of knowing how long it would take the Rebel analysts to discover it. Essentially, she has no reason to suspect that a marginally successful assault on the DS is even possible, and she doesn't know that there even is a weakness to exploit. All she seems confident of is the fact that Vader & Tarkin are tracking the Millennium Falcon. And yet, oddly, rather than switching ships at some planet somewhere or taking R2 somewhere else to get a complete technical analysis done, she leads the Imperial Forces directly to the secret base that she wants to protect and they want to destroy.

Dramatically and cinematically, it works. But it makes no logical sense whatsoever.