Well, this is what I think (I *may* be wrong in some slight details but overall I think I'm right

)
EF_BRIGHTLIGHT it's just a flag on a model and it's processed client side (light color, size, decay, etc), the server only sends another "flag" along with the entity data... and yeah, can be set only on another entity
and this has one more comunication with the module...
TE_DLIGHT creates another entity (info_target, at the specified origin) that emits one dynamic light that can be customized... this however has alot of comunications to the module setting each param
if you REALLY need TE_DLIGHT you can use it, but EF_BRIGHTLIGHT is a good alternative... for flares, model world-light glows, etc.
__________________