Seasonic is the OEM for most of the high end power supplies most companies sell today such as Corsair, Antec, XFX and many select others. Their own PSU lines are fabulous and highly efficient and stable. Not many other companies can boast of having as many high quality units as seasonic.
Seasonic isn't really sold where I live (South Africa), so I don't know them that well. XFX comes out here a little in their graphics cards mostly, so that's where it all starting going astray. We know brands like Cooler Master, Antec, Corsair, Thermaltake, etc. All in all though, I think I gave good advice