new to this router

I had no choice, based on information I received elsewhere, to purchase an ASUS RT-68U. Was using a Cisco WRVS4400N forever. I have the latest FW (3.0.0.4.374_4561), and I have a couple questions:
1. I thought this router had IPS, but cannot find any such reference from ASUS, guess yes or no will suffice here.
2. Is the ASUSWRT (available from ASUS) going to work or do I need Merlin?

Thanks All, Renman