1. Rice has better academic reputation (not a lot more, but still better).
2. Emory has two undergraduate colleges - Emory & Oxford. Oxford student pool is much weaker than Emory College.
So your Emory degree is diluted if you are from Emory college (yes, you get a liftup if you cannot get into EC, but OC).
Location wise, Houston and Atlanta are similar but Houston has a stronger economy.