Reflector

Hey guys. I am currently using a 400 watt HPS bulb and ballast with a 4ft white parabolic shade. I am basically wondering if this is a good reflector or if they all pretty much do the same thing. Thanks

i dunno but i am really interested in these as they seem to reduce temps as the bulb is hung vertically so the heat is dissipated to the sides rather than down, and it seems that these are really suitable for tent growing as the light intesityis projected straight downwards