I'm looking to replace my current power supply (it's about 5 years old now...) and see where the Supernova and XFX power supplies are "Tier 1" according to the Tier list found on the site. However the Antec PSU is a tier 2 and currently on sale more much less. I have a Radeon 7950 GPU and 2010 intel i7 processor - should I be comfortable with the Antec or should I pony up for the more expensive PSU?