One difference is the Elinchrom's diffuser is double layer.
If you don't want/need parabolic shape,
perhaps the PLM umbrellas are worth considering, especially for the cost savings.
Now Billy.
You know no self respecting New York City Photographer would be seen dead on an editorial set using a White Lighting Modifier.
Come on man, get with the party, call up Patrick and ask him Briese or Paul C. Bluff. He'll call Stevie M. and ask him if Paul C. Bluff is some kind of fashion statement and if Stevie doesn't know about they'll stick with the briese.
Now if the White Lightening people would paint them yellow and black they'd sell them by the boat load, but I don't think that's their style.
All kidding aside I think the reason 90% of the reason people use parabolics is because 90% of everything shot in NY is on some kind of white background and with all that bounce in those white rooms you have a little less spill which makes for a more direct looking light.
Not 90% unique but about a 10% difference.
But in regards to the Elinchrome. I think the head mounts way too close to the umbrella and without diffusion it is the same thing as using a smaller fixture. I always mounted a head on a C stand and pulled it back and forth for adjustments, but you had to be
careful because one assistant bumping the angle of the head could lose you a stop.
The profotos may take up more room than a small Nissan Truck, but at least the head is at a distance to the umbrellas so the light is pretty.
IMO
BC
P.S. Name and build quality aside that Paul Bluff stuff really does work well.