Superflower (TTGI) uses a less conservative amperage, wattage rating system than other top brands like Fortron, Delta, PC P&C. Antec also is a bit better, maybe Enermax is a closer direct wattage-wattage comparison. In other words, it's not worth 450W but then most systems don't actually
need 450W either, so basically it boils down to whether your system needs (plus reasonable margin, upgradability factor, etc) are lower than actual output.
Note that a high air movement above a heatsink is not always a good thing. Ideally a rear case fan below the PSU would remove most heated air, with cooler air flowing though the PSU. This allows any given psu to produce slight more power, but mostly, last longer. It seems nice on the surface to have a cooler running CPU, but the reality is that a CPU being a half dozen degrees cooler isn't important (so long as it's stable) compared to the wear on components with capacitors. Capacitors (and cheap sleeve bearing fans) are the two parts with mos significant lifespan reduction per temp rise, blah blah blah.
The Superflower is $57 on sale, before S/H. A better buy with about same true capacity and the large fan too, would be a Fortron FSP350-60PN,
$38,, or for even more power, a FSP400-60PN
$56 delivered,