Well, that's an OEM style FSP unit. Not particularly good, but
maybe not a dumpster fire starter either. No reviews so it's hard to say but judging on past experiences with FSP prior to the last few years, I'd say it might be a good idea to replace it with a better model when you can. Seriously, that's something I'd probably do.
That being said, for now it's probably ok with that configuration but just because it "works", don't get complacent and start thinking it's fine regardless what that guy on Tom's Hardware said. It's a cheap unit. No two ways about it.
Max ouput, and I mean MAX, which is a momentary figure, not what the unit can actually SUSTAIN, is only 360w according to the specifications on that unit's product page. So think of it as a 360w unit, not a 400w unit. Knowing that quality of unit I'd further recommend that you actually believe it cannot sustain more than maybe, at most, 300w continuously.
So it's probably cutting it very close as the recommendation for that card with the rest of the system is for a 380w unit.
http://www.realhardtechx.com/index_archivos/Page362.htm
Get a better one with a higher capacity sooner, not later. You want a good 450w unit to give yourself a little breathing room.