Onboard is better, but still can't compete with a soundcard. Nevermind the total lack of onboard sound for 5.1 digital encoding, or virtualization techs (Dolby Virtual Speaker, etc).
The Halo is a bit overkill, although it does compete with the Auzentech Forte and ASUS Essence STX. The Halo doesn't offer anything unique though, where Auzentech has full X-fi (for what its worth), and ASUS offers EAX 5 emulation.